1 - Atomic Structure and the Periodic Table...1 - Atomic Structure and the Periodic Table Describe the structure of an atom. • Atoms contain a nucleus (made of protons and neutrons)

1 - Atomic Structure and the Periodic Table

Describe the structure of an atom.

• Atoms contain a nucleus (made of protons and neutrons)

• surrounded by electrons which orbit around in

• shells

Why are atoms neutral? (2 marks)

• The number of protons = the number of electrons

• The charges cancel

Where are elements with similar properties found in the periodic table?

• The same group (vertical column) • E.g. group 1, group 2…

Which groups are the noble gases, the alkali metals and the halogens found in?

• Noble gases = group 0 • Alkali metals = group 1 • Halogens = group 7

In the periodic table, where are the mass

number and atomic number found and what do they tell you about an element?

• Mass number: protons + neutrons

• Atomic number: protons (same as the

number of electrons)

Draw an atom of chlorine (1 mark)

Write the electron configuration of sodium (1

mark)

• 2,8,1

(you need to be able to do this for every element up to Ca)

Describe and explain the trend in reactivity down group 1 ( 4 marks)

• Reactivity increases down group 1 • Atoms get bigger (more shells) • Outer electron gets further away from the

nucleus. • Attraction between nucleus and outer

electron is weaker. • Electron more easily lost.

Describe and explain the trend in reactivity down group 7 (4 marks)

• Reactivity decreases down group 7 • Atoms get bigger • Electron being gained is further from the

nucleus • Therefore attraction is weaker • So electron is harder to gain

Describe and explain the importance of the work of Mendeleev (3 marks)

• He left gaps for undiscovered elements • He ordered atoms in order of their atomic

weight • He organised elements into groups based

on their reactivity

Describe the process of filtration

• Used to separate an insoluble solid from a liquid e.g. to separate sand from water

Describe the process of evaporation

• Used to separate a soluble solid from a liquid e.g. to separate salt from saltwater

Describe the process of distillation

• Used to separate a soluble solid from a liquid and keep both the liquid and the solid.

Describe the process of chromatography and explain why it is used (Required Practical 6)

• Used to separate inks.

Method:

• Place a pencil line of a piece of chromatography paper (stationary phase)

• Use pencil so ink doesn’t run • Place dots of known inks and an unknown

ink on the link. • Place in the solvent (mobile phase) in a

beaker (below the pencil baseline) • Leave to develop • Remove and leave to dry. • Compare known with unknown to identify

what inks are in the unknown sample. • Calculate Rf values

Calculating Rf values:

• VALUE WILL ALWAYS BE LESS THAN 1

List the properties of transition metals

• Form coloured compounds • Conduct electricity • Conduct heat • Malleable (can be hammered into shapes) • Ductile (can be pulled into wires) • Hard • Strong • High melting points

2 - Structure, Bonding and Properties

Describe ionic bonding (4 marks)

1. Between a metal and a non-metal. 2. Transfer of electrons from the metal to the

non-metal. 3. Produces a positive metal ion and a negative

non-metal ion. 4. Oppositely charged ions held together by an

electrostatic interaction.

e.g. NaCl, CaCl2, MgO, Na2O… Make sure you use the example in the question eg: Na transfers one electron to chlorine to form Na+

and Cl-. Ions held together by an electrostatic interaction.

Draw HCl (2 marks)

Draw Cl2

Draw O2

Draw CO2

*You have to be able to draw the covalent bond

between a variety non-metals

Draw CH4

Draw NaCl

Draw MgO

*You have to be able to draw the ionic bond between a variety of metals and non-metals

Draw CaCl2

What is the formula of the ionic compound formed between magnesium and chlorine?

1. Write down the charges on your ions:

Group 1 = +1 Group 2 = +2 Group 3 = +3 Group 6 = -2 Group 7 = -1 Complex ions: Nitrate = NO3

-

Sulphate = SO42-

hydroxide = OH-

2. Magnesium = Mg2+ 3. Chloride = Cl- 4. Drop the charge, swap the number:

Mg2+ Cl-

Mg2 Cl = MgCl2

Describe the structure and bonding in a metal?

(2 marks)

• Lattice of positive metal ions • Surrounded by a sea of delocalised

electrons.

What are the different allotropes of carbon? (allotrope = different forms of the same

element)

• Diamond • Graphite • Graphene (one sheet of graphite) • Graphane • Fullerenes (football shaped) • Carbon nanotubes

Why are atoms neutral? (2 marks)

• Equal number of positive protons and

negative electrons • Cancel.

Why do graphite/grapheme/fullerenes/carbon nanotubes conduct electricity?

(3-4 marks)

• Delocalised electrons • Between the layers • Free to move • Carry charge • Each C has 3 bonds.

Why to atoms react? (1 mark)

• To gain a full outer shell.

Why is graphite slippery? / Why can graphite be used in pencils?

(asking the same thing!) (3 marks)

• Weak interactions/forces • Between the layers • Easy to break.

What is a covalent bond? (2-3 marks)

• Shared pair of electrons • Between 2 non-metals

HT answer:

• Electrostatic attraction between the • Positive nuclei and the • Shared pair of negative electrons

Why does silicon dioxide have a high melting point? / Why can silicon dioxide be used to line

furnaces? (asking the same thing!)

(4-5 marks)

• Each Si has 4 bonds and each O has 2 bonds.

• All bonds are covalent. • Giant covalent structure. • Many strong covalent bongs need to be

broken • So has a high melting point.

How does the covalent bond between HCl form? (3 marks)

• H has 1 outer shell electron • Cl has 7 outer shell electrons • Each share 1 electron to get a full outer shell.

Why can ionic compounds NOT conduct electricity when solid?

(2 marks)

• Ions • In fixed position in the ionic lattice • Cannot carry charge.

Why do simple molecules have low boiling

points? / Why is methane a gas a room temperature?

(asking the same thing!) (3 marks)

• Weak interactions/forces • Between molecules • Easy to break.

Why can ionic compounds conduct electricity when molten?

(2 marks)

• Ions • Free to move and carry charge

Why do simple molecules NOT conduct electricity? (2 marks)

• No delocalised electrons so • Cannot carry a charge.

Why does diamond NOT conduct electricity? (2 marks)

• No delocalised electrons so • Cannot carry a charge.

Why is diamond hard? (4-5 marks)

• Each carbon has 4 covalent bonds • Giant covalent structure • Strong bonds hard to break.

Why can metals conduct electricity? / Why is copper used in wires?

(asking the same thing!) (2-3 marks)

• Delocalised electrons • Free to move and carry charge through the

metal structure.

Why does diamond have haigh melting point? (4 marks)

• Each C has 4 bonds • All bonds are covalent. • Giant covalent structure. • Many strong covalent bongs need to be

broken • So has a high melting point.

Explain the difference in boiling point of HCl and NaCl. (6 marks)

** you can be asked to compare the boiling point of any two compounds so you need to make sure you

can work out what the bonding is!**

• HCl is simple covalent • Exists as molecules • Weak interactions between molecules • Easy to break

• NaCl is ionic • Exists in 3D ionic lattice • Strong electrostatic attraction • Between Na+ and Cl-/oppositely charged

ions • Need a lot of energy to break

• So NaCl has a higher boiling point than HCl

Draw the structure of a metal (2 marks)

Why can metals be hammered into shapes? (2 marks)

• Layers of metal ions • Slide over eachother. • This does not disrupt the structure of the

metallic bond.

How big are nanoparticles?

One billionth of a metre. Or 10-9m Or Very tiny

What is the difference between thermosetting and thermosoftening polymers?

Thermosetting polymers have cross-linked chains. They are formed by putting them into a mould and heating. The resulting structure cannot be reshaped.

Thermosoftening polymers have weak interactions between polymer chains. They can be reshaped when heated.

What are the environmental advantages and disadvantages of using nanoparticles?

• Advantages: long-lasting (e.g. using in tennis

balls), antibacterial properties (e.g. used in smelly socks).

• Disadvantages: Could be toxic if they entered

the bloodstream.

Draw and name the polymer formed by ethene (4 marks)

1 – for n before monomer 2 – for breaking double bond and drawing 2 bonds outside of brackets 3 – for brackets 4 – name = poly(ethene)

Sketch the structure of graphite ( 2 marks)

3 - Quantitative Chemistry: Calculations

What is the relative molecular mass, Mr? The sum of the mass numbers in a molecule or compound

What is the Mr of LiCl? 3 + 35.5 = 38.8

What is the Mr of Ca(OH)2

40 + (2x16) + (2x1) = 74

What equation links mass, molecular mass and moles? Mass = molecular mass x moles m = Mr x n

Rearrange m = Mr x n to calculate n. n = m / Mr

What equation links moles, concentration and volume? Moles = concentration (in mol/dm3) x volume (in dm3) n = c x v

What equation links mass, concentration and volume? Mass (in g) = concentration (in g/dm3) x volume (in dm3) m = c x v

What is the maximum mass of magnesium oxide that can be formed from 5 g of Magnesium and 12 g of oxygen? (4 marks) – Limiting reagent question! (They have given you information about both reactants)

2Mg + O2 à 2MgO

1. Work out the moles of Mg 2. Work out the moles of O2 3. Work out which moles are in excess and which

are limiting – the limiting you use in your reacting masses calculation.

4. Write down the Mr of the limiting reagent and MgO

5. Work out the molar ratio 6. Work out the moles of MgO that would be

produced 7. Work out the mass of MgO

2Mg + O2 à 2MgO

m = 5g m = 12g Mr = 24 Mr = 16 n = 5/24 = 0.21

n = 12/16 = 0.75

0.21 moles of Mg needs 0.21/2 = 0.105 moles of O2 We have 0.75 g of O2, so O2 is in excess and Mg is limiting – USE MOLES OF Mg:

m = 40 x 0.21 = 8.3g Mr MgO = 24 + 16 = 40 n = 0.21 (as 1:1)

*you have to be able to do this for any equation with any ratio and any quantities given

What is the maximum mass of magnesium oxide that can be formed from 5 g of Magnesium? (3 marks)

2Mg + O2 à 2MgO 1. Work out the moles of Mg 2. Write down the Mr of Mg and MgO 3. Work out the molar ratio 4. Work out the moles of MgO that would be

produced 5. Work out the mass of MgO

2Mg + O2 à 2MgO

m = 5g m = 40 x 0.21 = 8.3g

Mr = 24 Mr = 24 + 16 = 40

n = 5 / 24 = 0.21 n = 0.21 (as 1:1)


What is a titration? A neutralisation reaction used to find the unknown concentration of the acid or alkali using a known concentration of the other. (required practical 2)

Name the apparatus used in a titration.

Calculate the concentration of sodium hydroxide if 25 cm3 needed 23.25 cm3 of 0.1 mol/dm3 hydrochloric acid for neutralisation ( 3 marks) (HT only)

HCl + NaOH à NaCl + H2O

1. Write down the volumes in dm3 (cm3 /1000) of HCl and NaOH

2. Write down the concentration of HCl 3. Calculate the moles of HCl 4. Calculate the molar ratio 5. Calculate the concentration of NaOH

HCl + NaOH à NaCl + H2O

n = 0.1 x 0.02325 = 0.002325

n = 0.002325

c = 0.1 mol/dm3 c = 0.002325/0.025 = 0.093 mol/dm3

v = 0.02325 dm3 v = 0.025 dm3


What is the % yield if 40 g of C was expected but only 32.5 g were produced? (Triple only)

A + B à C

% yield = actual yield x 100 Theoretical yield = 32/40 x 100 = 80 % *you have to be able to do this for any equation with any ratio and any quantities given

Calculate the atom economy for the production of CaCl2 in the following equation: (Triple only)

2HCl + Ca(OH)2 à CaCl2 + 2H2O 1. Calculate the Mr of all the products (INCLUDING

THE MOLAR RATIO – the only time you do this!) 2. Calculate the Mr of all the CaCl2 (INCLUDING

THE MOLAR RATIO – the only time you do this!) 3. Calculate the atom economy: % atom economy = Mr desired product (CaCl2) x100 Mr all products (CaCl2 + 2H2O) = 40 + (2x16) + (2x1) x100 [40 + (2x16) + (2x1)] + [(4x1) + (2x16)] = (74 / 110) x 100 = 67.3 % *you have to be able to do this for any equation with any ratio and any quantities given

What volume does 1 mole of any gas occupy at standard temperature and pressure (298 K and 10kPa)? (Triple only)

24 dm3

At room temperature and pressure, what volume does 0.3 moles of O2 occupy? (Triple only) 0.3 moles x 24 dm3 = 7.2 dm3

What volume of oxygen is needed to completely burn 200 cm3 of butane? (Triple only)

C4H10 + 6.5O2 à 4CO2 + 5H2O

200 x 6.5 = 1300 cm 3 or 1.3 dm3


100 cm3 of methane was reacted with 500 cm3 of oxygen. What is the total volume of gas at the end of the reaction and how much of each gas is there? (Triple only)

CH4 + 2O2 à CO2 + 2H2O

100 cm3 of methane reacts with 200 cm3 of oxygen. 100 cm3 of methane produced 100 cm3 of carbon dioxide. At the end there is: • 500 – 200 = 300 cm3 of oxygen • 100 cm3 of carbon dioxide • Total volume of gas – 300 + 100 = 400 cm3


5 - Chemical Changes: Salts and Electrolysis

What is oxidation in terms of oxygen? (1 mark) Gain of oxygen

What is reduction in terms of oxygen? (1 mark) Loss of oxygen

What are oxidation and reduction in terms of electrons? (2 marks) Oxidation is loss of electrons Reduction is gain of electrons

Think OILRIG!

Are the following oxidation or a reduction?

1. Na+ + e- à Na Reduction

2. 2Cl- à Cl2 + 2e- (Can also be written 2Cl- - 2e-à Cl2)

Oxidation

Examples of acids: • Hydrochloric acid (HCl) • Sulphuric acid (H2SO4) • Nitric acid (HNO3)

Examples of alkalis:

• Metal hydroxide (e.g. sodium hydroxide, NaOH))

• Metal oxide (e.g. sodium oxide, Na2O)

Naming salts The salt produced is named from the acid used:

Acid used Metal salt produced Hydrochloric acid Chloride

Sulphuric acid Sulphate Nitric acid nitrate

What is the ionic equation for neutralisation? (1 mark)

• H+ + OH- à H2O

Acid + alkali à salt + water e.g. hydrochloric acid + sodium hydroxide à sodium chloride + water

• Neutralisation reaction

Acid + carbonate à salt + water +

carbon dioxide

e.g. nitric acid + lithium carbonate à lithium nitrate + water + carbon dioxide

Acid + metal à salt + hydrogen

e.g. sulfuric acid + potassium à potassium sulfate + hydrogen

What is a strong acid? (2 marks)

• Fully dissociates • In solution

e.g. HCl à H+ + Cl-

What is a weak acid? (2 marks)

• Partially dissociates • In solution

e.g. CH3OOH H+ + CH3COO-

What is the pH of a strong acid and a weak acid? Strong acid = pH 0-2 (red in universal indicator) Weak acid = pH 3-5 (orange/yellow in universal indicator)

How can you test to see whether a solution is neutral? Universal indicator turns green Or pH meter gives a reading of 7.0 (most accurate)

What is electrolysis? (1 mark)

• Splitting up ionic compounds using electricity

Describe and explain how crystals of copper sulfate can be produced (6 marks)

(Required practical 1)

1. Add an excess of copper oxide to sulphuric acid to react via the following equation:

Copper oxide + sulphuric acidàcopper sulfate + water CuO(s) + H2SO4(aq) à CuSO4 (aq) + H2O(l)

2. An excess of copper oxide is added to ensure all of the sulphuric acid reacts.

3. Filter off any unreacted CuO(s) ß insoluble. 4. Pour the copper sulfate solution (blue) into

an evaporating dish. 5. Heat using a Bunsen burner to remove half

the water and start crystallisation. 6. Leave to evaporate, leaving crystals of pure

copper sulfate (CuSO4)

Why does the electrolyte need to be molten or in solution for electrolysis to work? (2 marks)

• So the ions • Can move

Label a diagram showing the set-up of equipment used in electrolysis


Describe and explain how crystals of copper lead iodide using the following equation

(4 marks) Pb(NO3)2(aq) + 2KI(aq) à PbI2(s) + 2KNO3(aq)

1. Add lead nitrate to potassium iodide solution in a 1:2 ratio.

2. Solid lead iodide (yellow) is produced. 3. Filter off the solid, insoluble lead iodide

from the unreacted lead nitrate and potassium iodide and potassium nitrate solution products.

4. Wash with distilled water. 5. Leave to dry.

Describe the electrolysis of brine/sodium chloride solution/ NaOH(aq) and explain why

three products are made (6 marks)

• Ions in solution = Na+, Cl-, H+ and OH- • Na+ and Cl- from sodium chloride • H+ and OH- from the water (solution) • H+ moves to negative electrode to produce

hydrogen gas (H2) o Half equation: 2H+ + 2e- à H2

• Cl- moves to positive electrode to produce chlorine gas (Cl2)

o Half equation: 2Cl- à Cl2 + 2e- • Na+ and OH- left in solution form sodium

hydroxide (NaOH). •

**THE MOST REACTIVE POSITIVE ION STAYS IN SOLUTION

Describe the process of electrolysis of aluminium oxide (Al2O3), stating the products and explaining how they are formed (6 marks)

• Heated until molten (melted) • Cryolite added to lower melting point • Ions = Al3+ and O2- • Al3+ moves to negative electrode to produce

aluminium (Al) o Half equation = Al3+ + 3e- à Al

• O2- moves to positive electrode to produce oxygen (O2)

o Half equation = 2O2- à O2 + 4e- • O2 reacts with carbon electrodes to form

carbon dioxide (CO2) o C(s) + O2(g) à CO2(g)

• Carbon electrodes therefore need to be replaced frequently as they ware away.

State the chemical tests for the products of electrolysis of NaOH(aq) and describe their uses

(6 marks) Test for products:

• Cl2 – bleaches litmus paper • H2 – lit splint pops • NaOH (pH 14) – turns universal indicator

paper blue Uses of products:

• Cl2 – bleach • H2 – making margarine • NaOH - making soap

2 types of electrolysis: 1. Molten Look at the

e.g. PbBr2 (l) state symbol!

Ions present: Pb2+ Br- 2. Aqueous

e.g. CaCl2(aq)

Ions present: Ca2+ Cl- H+ OH-

**In aqueous electrolysis, THE MOST REACTIVE + ION STAYS IN SOLUTION and the LEAST REACTIVE FORMS THE PRODUCT at the cathode. At the anode, if NO3

-, OH- or SO42- are present,

oxygen is produced. Writing half-equations:

1. Look at the charge on the ion 2. Swap it around to write the number of

electrons e.g. Ca2+ +2e- à Ca e.g. 2O2- -4e- à O2

The Reactivity Series (learn!)

A more reactive element can displace a less reactive element within a compound. e.g. CuSO4 + Mg à MgSO4 + Cu

List the metals that can be extracted using carbon (reduction). Zinc Iron Tin Lead Copper

Which metals do not need to be extracted and why?

Gold Platinum Are unreactive and so exist native. They exist as pure elements and do not need to be extracted from compounds.

Which elements need to be extracted by electrolysis and why?

Potassium Sodium Calcium Magnesium Aluminium They are too reactive and therefore cannot be displaced by carbon from their compounds

6 - Energy Changes

Define exothermic (2 marks)

• Gives out heat energy • To the surroundings

ΔH is negative

Describe how you could determine the point of

neutralisation in an acid-base reaction by measuring the temperature.


• Add 25 cm3 of acid to a polystyrene cup (for insulation)

• Record the start temperature • Add 5 cm3 of alkali and record the temperature • Add 5 cm3 of alkali until you have added 40 cm3

in total, recording the temperature each time. • Plot a graph of volume of alkali added (x axis)

against temperature (y axis) • Draw two lines of best fit. • Find the intersect of the two lines and read the

value off the x-axis: This is the volume of alkali needed to neutralise the 25cm3 of acid.

Volumeofalkaliadded**Use the values in the question (the values here are just an example) Acid/alkali may be the other way around – read the question!

Define endothermic (2 marks)

• Take in heat energy • From the surroundings

ΔH is positive

Describe a simple experiment you could do to find out whether a reaction is exothermic or

endothermic.

• Measure the change in temperature. • If the temperature increases (gets hotter) =

exothermic • If the temperature decreases (gets colder) =

endothermic

Enthalpy change (ΔH) using bond enthalpies: ΔH = Sum of bonds broken – sum of bonds made

Calculate the enthalpy change of the following reaction using the following bond enthalpies:

CH4 + 2O2 à CO2 + 2H2O

ΔH = [(4x412) + (2x498)] - [(2x743) + (4x463) = [1648 + 996] - [1486 + 1852) = 2644 – 3338 = -694 kJ/mol ** you have to be able to do this for any equation

Bond Mean bond enthalpy (kJ/mol) C-H 412 O=O 498 C=O 743 O-H 463

What equation can be used to calculate the heat energy released by a reaction?

q = m x c x ΔΤ

heat energy (J) = mass of water x specific heat capacity of water (4.2) x change in temperature

What equation allows us to calculate the enthalpy change of a reaction in kJ/g?

ΔH = q / mass of fuel burned (g) What equation allows us to calculate the enthalpy change of a reaction in kJ/mol?

ΔH = q / moles of fuel burned (moles)

**Remember moles = mass / Mr!!

1.5 g of ethanol (C2H5OH) was burned. This caused the temperature of 50 cm3 of water to rise by 14 oC. Calculate the enthalpy change for the reaction in kJ/mol. q = mcΔT = 50 x 4.2 x 14 = 2940 J n = m/Mr = 1.5/((12x2)+16+6) = 1.5 / 46 = 0.0326 moles of ethanol ΔH = q/n = 2.940 KJ / 0.0326 ß don’t forget to convert q to kJ = - 90.18 kJ/mol ß add – sign as reaction gets hotter so is exothermic

1.2 g of ethanol (C2H5OH) was burned. This caused the temperature of 100 cm3 of water to rise by 8 oC. Calculate the enthalpy change for the reaction in kJ/g. q = mcΔT = 100 x 4.2 x 8 = 3360 J ΔH = q/m = 3.360 KJ / 1.2 ß don’t forget to convert q to kJ = - 2.8 kJ/mol ß add – sign as reaction gets hotter so is exothermic

Name 3 types of chemical cells (Triple only)

1. Simple cells 2. Non-rechargeable cells (run out once the

chemical reactions in the call have run out) 3. Rechargeable cells (can be recharged by

applying an external electrical current to reverse the reaction)

Describe the hydrogen fuel cell (Triple only)

Where do the raw materials in a hydrogen fuel cell come from? Hydrogen – from fossil fuels Oxygen – from the air

What are the advantages and disadvantages of non-rechargeable cells? Advantages: Cheap, small, portable source of electricity Disadvantages: waste issues – go to landfill. Cannot be disposed of in normal household waste due to chemicals inside them.

What are the reactions taking place at each electrode in a hydrogen fuel cell? (use half equations) Use these half equations to write the overall reaction taking place in a hydrogen fuel cell (Triple only) Anode: O2 + 4H+ + 4e- à 2H2O Cathode: 2H+ +2e- à H2

Overall reaction: 2H2 + O2 à 2H2O

What are the advantages and disadvantages of rechargeable cells? Advantages: Less waste, small, portable source of electricity Disadvantages: still some waste issues – go to landfill. Cannot be disposed of in normal household waste due to chemicals inside them.

What are the advantages and disadvantages of fuel cells? Advantages: water is the only product, so cleaner than burning fuels for electricity which produce CO2 and cause global warming. Continuous source of fuel into fuel cell so no need to recharge. Disadvantages: more H2 from fossil fuels, which are non-renewable. Current engines would need to be modified which is expensive.

7 - The Rate and Extent of a Chemical Reaction

What is meant by the term ‘rate of reaction’ (2 marks)

• The speed at which reactants • are converted into products

How does increasing the concentration affect the rate of reaction? Explain your answer.

(4-5 marks) *you also have to be able to explain decreasing the

concentration*

• increases the rate of reaction • more particles • in same volume • more collisions • that are successful

How does increasing the temperature affect the

rate of reaction? Explain your answer. (4 marks)

*you also have to be able to explain decreasing the temperature*

• increases the rate of reaction • particles have more energy • move more • more collisions • that are successful

How does increasing the pressure affect the rate of reaction? Explain your answer.

(4-5 marks) *you also have to be able to explain decreasing the

pressure*

• increases the rate of reaction • same number of particles • in a smaller volume • more collisions • that are successful

How does decreasing the surface area affect

the rate of reaction? Explain your answer. (4 marks)

*you also have to be able to explain increasing the surface area*

• decreases the rate of reaction • less surface available for particles to react on • so less collisions • than are successful.

How does adding a catalyst affect the rate of reaction? Explain your answer.

(4 marks)

• speeds up the reaction • provides another route for the reaction • that requires less energy • is not changed itself so can be reused.

What is collision theory? (2 marks)

• particles must collide • with enough energy for a reaction to happen.

What five factors can affect the rate of a chemical reaction?

• Temperature • Pressure • Catalyst • Concentration • Surface area

How does the rate of reaction change with time at 40 oC

(3 marks)

• Fast initially • Slows • Then stops

Explain your answer (3 marks)

• because the reactants are used up • So the concentration decreases • So there is less chance of successful collision

Time

Amou

ntofp

rodu

ct

evolved

20°C

30°C

40°C

Define Le Chalelier’s Principle A system at equilibrium will move to oppose the change created by any external conditions that are applied

Define dynamic equilibrium

A reversible reaction in a closed system (nothing can get in or out). The concentration of reactants and products remains constant unless an external change in conditions is applied

What is the symbol used in a reversible reaction (an equilibrium)?

Describe and explain how the yield of C would change if the pressure of the following reaction

was increased (3 marks)

A + 2B C + D

• The yield of C would increase • There are 3 moles on the left and 2 on the right • The equilibrium would shift to the right (to the

side with less moles) to try and reduce the pressure.

Describe and explain how the yield of C would change if the temperature of the following

reaction was increased (3 marks)

A + 2B 2C + D ΔH = -190 kJ/mol

• The yield of C would decrease • The forwards reaction is exothermic • The reaction would move to the left in the

endothermic direction to try and reduce the increase in temperature.

Describe and explain how the yield of C would change if the pressure of the following reaction

was increased (3 marks)

A + 2B 2C + D ΔH = -160 kJ/mol

• The yield of C would stay the same • There are the same number of moles on each

side. • The equilibrium position would not change

Describe and explain how the yield of D would change if the concentration of C in the

following reaction was increased (2 marks)

A + 2B C + D ΔH = -120 kJ/mol

• The yield of D would decrease • The equilibrium would move to the left to try and

reduce the increased amount of C

Describe and explain how the yield of C would change if a catalyst was added to the following

equilibrium (3 marks)

A + 2B 6C + D ΔH = +90 kJ/mol

• The yield of C would not change • The equilibrium would be established quicker as

the catalyst would speed up the rate of reaction in both directions equally.

• The position of equilibrium would not change.

7 - Organic Chemistry

What is crude oil and how is it formed?

Crude oil is a mixture of hydrocarbons (1 mark) It formed millions of years ago when plankton became trapped under layers of sediment and did not decompose. This has turned into crude oil over time. (1 mark)

What is a hydrocarbon ( 1 mark)

A compound that contains carbon and hydrogen only

What is an alkane? (1 mark)

A hydrocarbon that contains single bonds only

What is an alkene? (1 mark)

A hydrocarbon that contains double bonds

Name and draw the first four alkanes

Name and draw the first four alkenes

Explain why ‘methene’ does not exist (2 marks)

• Methene would only have one carbon • Therefore it could not contain a C=C double

bond

What is the general formula of an alkane (1 mark)

CnH2n+2

What is the general formula of an alkene (1

mark)

CnH2n

What is the general formula of an alcohol (1 mark)

CnH2n+1OH

Define saturated and unsaturated

• Saturated = contains single bonds only • Unsaturated = contains double bonds

Describe the chemical test for unsaturation (double bonds/alkenes) (2 marks)

• Bromine water • Orange to colourless

What is the general formula of a carboxylic acid (1 mark)

CnH2n+1COOH

Draw ethanoic acid (1 mark) (triple only)

Draw and name the first four alcohols

Draw ethyl ethanoate and state what homologous series this molecule belongs to

This is an ester

Define homologous series

A group of compounds with the same general formula

Explain how fractional distillation separates crude oil into useful fractions (4 marks)

• Crude oil is evaporated by heating • The molecules move up the fractionating

column with the temperature gradient – hot at the bottom and cooler at the top)

• Different fractions condense at their boiling point.

• Different fractions have different boiling points:

• Large molecules have higher boiling points and are found at the bottom

• Small molecules have higher boiling points and condense at the top.

What is cracking (1 mark)

Large hydrocarbons are broken down into smaller, more useful fractions

Describe the process of cracking (2 marks)

• Heat to vaporise • Pass over a catalyst

State the differences between fractional distillation and cracking

• Fractional distillation is a physical process,

cracking is a chemical change • Fractional distillation separates a mixture,

cracking breaks large molecules into small ones

Write an equation to show how decane, C10H22, is broken down into butane, propane and

propene

C10H22 à C4H10 + C3H8 + C3H6

Define complete combustion

• Complete combustion is when a fuel is completely burned in oxygen.

• The products are carbon dioxide and water

e.g. CH4 + 2O2 à CO2 + 2H2O

Define incomplete combustion

• Complete combustion is when a fuel is completely burned in oxygen.

• The products are carbon monoxide or carbon and water

e.g. CH4 + 1.5O2 à CO + 2H2O CH4 + O2 à C + 2H2O

Name the two types of polymerisation, state the monomers used and describe how they

react together to form polymers

• Addition Monomers: alkenes Process: The double bond breaks and forms single bonds to a neighbouring alkene monomer

• Condensation (triple only) Monomers: di-carboxylic acids and di-alcohol Process: two monomers react together and form a ester bond between monomers, producing water as a bi-product Or Monomers: dicarboxylic acids and diamines Process: two monomers react together and form an amide bond between monomers, producing water as a bi-product

Draw and name the addition polymer formed by ethene (4 marks)

1 – for n before monomer 2 – for breaking double bond and drawing 2 bonds outside of brackets 3 – for brackets 4 – name = poly(ethene)

Draw and name the condensation polymer formed when a diacid acid reacts with a diol (4

marks) (triple only)

Draw and name the condensation polymer formed when a diacid reacts with a diamine (4

marks) (triple only)

Define DNA (triple only)

Deoxyribonucleic acid

Using the amino acids show (glycine), draw the dipeptide that would form (triple only)

Draw and name the product of reaction when ethene reacts with bromine, Br2 (triple only)

1,2-dibromoethane

Draw and name the product of reaction when ethene reacts with water (triple only)

ethanol

Draw the mechanism for the reaction of ethene with bromine (triple only, grade 9)

Draw the mechanism for the reaction of ethene with water (triple only, grade 9)

Draw the product of the oxidation of ethanol (triple only)

Alcohols oxidise to form carboxylic acids

Describe the structure of DNA

• 2 Polymer chains in a double helix • 4 nucleobases hydrogen bonded together

8 - Chemical Analysis

Define a ‘pure’ substance (1 mark)

Contains only one type of atom/molecule

What is a formulation? (1 mark)

A mixture of chemicals with a consistent composition so all products are the same

What is the chemical test for oxygen? (2 marks)

• Glowing splint • Relights

What is the chemical test for hydrogen? (2 marks)

• A lit splint • pops

What is the chemical test for carbon dioxide?

(2 marks)

• Limewater • Turns cloudy

What is the chemical test for chlorine? (2 marks)

• Litmus paper • Bleaches white

What is the chemical test for metal cations and

describe this process? (triple only)

• Flame test • Clean a metal loop with hydrochloric acid • Dip into the metal salt you are testing • Observe the colour of the flame

Cation Colour of flame Li+ Crimson Na+ Yellow K+ Lilac Cu2+ Green Ca2+ Orange-red

What is the chemical test for transition metal cations? (triple only)

• Add NaOH solution • Observe the colour of the precipitate formed

Cation Colour of precipitate Fe2+ Fe(II) Green Fe3+ Fe(III) Brown Al3+ White (redissolves in excess NaOH) Cu2+ Blue Mg2+ White Ca2+ White

Write an equation, including state symbols, to

show how NaOH can be used as a chemical test for Cu ions in CuSO4 (triple only)

CuSO4 (aq) + 2NaOH (aq) à Na2SO4 (aq) + Cu(OH)2 (s)

* you have to be able to do this for any metal compound reacting with NaOH

Write an ionic equation, including state symbols, to show how NaOH can be used as a chemical test for Cu ions in CuSO4 (triple only)

Cu2+ (aq) + 2OH- (aq) à Cu(OH)2 (s)

* you have to be able to do this for any metal compound reacting with OH-

What is the chemical test for a carbonate ion,

CO32-? (3 marks) (triple only)

• Add acid • (acid + carbonate à salt + water + carbon

dioxide) • Bubble the gas produced through limewater • If the limewater turns cloudy it means CO2

was produced, which means a carbonate was present

What is the chemical test for a sulfate ion, SO42-? (2 marks) (triple only)

• Add barium chloride, BaCl2 • If a sulphate is present you will see a white

precipitate of barium sulfate

Write an ionic equation, including state symbols, to show how barium chloride is used as the chemical test for sulphate ions in CuSO4

(triple only)

SO42- (aq) + Ba2+ (aq) à BaSO4 (s)

BaSO4 (s) is a white precipitate

Write an equation, including state symbols, to show how barium chloride is used as the

chemical test for sulphate ions in CuSO4 (triple only)

CuSO4 (aq) + BaCl2 (aq) à BaSO4 (s) + CuCl2 (aq)

BaSO4 (s) is a white precipitate

Describe the chemical test for a halide ions Cl-, Br-, I-? (3 marks) (triple only)

• Add silver nitrate (AgNO3) • Observe the colour of the precipitate (as in

the table below):

Anion Colour of precipitate Cl- White (AgCl) Br- Cream (AgBr) I- Yellow (AgI)

• It can be difficult to distinguish between the

colours of the precipitates. These tests can be confirmed using dilute and concentrated ammonia (NH3) as follows:

Precipitate Test using NH3 AgCl Dissolves in dilute NH3 AgBr Dissolves in concentrated NH3 AgI Insoluble in NH3

Write an equation, including state symbols, to show how silver nitrate is used as the chemical test for halide ions (Cl-, Br-, I-) in Lithium halide

compounds (triple only)

LiCl (aq) + AgNO3(aq) à AgCl(s) + LiNO3(aq) White ppt

LiBr (aq) + AgNO3(aq) à AgBr(s) + LiNO3(aq)

Cream ppt

LiI (aq) + AgNO3(aq) à AgI(s) + LiNO3(aq) yellow ppt

Write an ionic equation, including state

symbols, to show how silver nitrate is used as the chemical test for halide ions (Cl-, Br-, I-)

(triple only)

Cl- (aq) + Ag+(aq) à AgCl(s)

White ppt

Br- (aq) + Ag+(aq) à AgBr(s) Cream ppt

I- (aq) + Ag+(aq) à AgI(s)

Yellow ppt

Explain how flame emission spectroscopy is used to detect metal cations (triple only)

• The sample is heated in a flame. The energy

excites electrons making them jump into higher energy levels.

• When they fall back to lower energy levels, the energy is released as light energy.

• The wavelength of the light is analysed through a spectrometer.

• Each element emits light at a characteristic wavelength called its ‘line spectrum’.

What are the advantages and disadvantages of instrumental methods

Advantages:

• Quick • Sensitive (can use a very small sample) • Accurate

Disadvantages:

• Expensive • Special training needed to use equipment • Results need to be compared with spectra

of known substances

9 - Chemistry of the Atmosphere

State the composition of the atmosphere today (3 marks)

• Nitrogen – 78 % • Oxygen – 21 % • Carbon dioxide – 0.03 %

Describe the main differences between the early atmosphere and the atmosphere today

• Lots more nitrogen (none in early

atmosphere vs 78 % now) • Lots more oxygen (none in early

atmosphere vs 21 % now) • Less carbon dioxide (0.03 % now vs 96 %

then)

Describe and explain the change in the concentration of carbon dioxide in the Earth’s

atmosphere over time (3 marks)

• It has decreased because:

• Photosynthesis of plants • Dissolved in the oceans • Formed carbonate rocks (eg calcium

carbonate/limestone) • Locked up in fossil fuels

Describe and explain the change in the concentration of oxygen in the Earth’s

atmosphere over time (2 marks)

• It has increased because:

• Photosynthesis of plants

Explain how carbon dioxide cause global warming/ Describe how carbon dioxide helps

to maintain temperatures on Earth. (3 marks) (grade 9)

• Carbon dioxide allows short wavelength

radiation to pass through the atmosphere to the Earth’s surface

• Carbon dioxide absorbs outgoing long wavelength radiation

• This traps the heat in the atmosphere.

State the main greenhouse gases

• Carbon dioxide – CO2 • Methane – CH4

Write an equation for the incomplete combustion of ethane to form a gaseous product (2 marks – 1 for formulae, 1 for

balancing)

C2H6(g) + 2.5O2(g) à 2CO(g) + 3H2O (l)

Write an equation for the incomplete combustion of propane to form a solid product

(2 marks – 1 for formulae, 1 for balancing)

C3H8(g) + 2O2(g) à 3C(s) + 4H2O (l)

State the environmental effects of the products of combustion

Gas Effect

Carbon dioxide - CO2 Global warming Methane – CH4 Global warming

Carbon monoxide – CO Toxic Particulates - C Global dimming

Sulfur dioxide – SO2 Acid rain Nitrogen oxides - NOx Acid rain

Write an equation for the combustion of propanol (2 marks – 1 for formulae, 1 for

balancing)

C3H7OH(g) + 5O2(g) à 3CO2(s) + 4H2O (l)

What are the four main contributions to global warming made by humans?

• Deforestation • Burning fossil fuels • Animal farming • Decomposition of landfills

What is a carbon footprint?

A carbon footprint is an estimate of the impact that activities have on climate change – such as making a product, living a lifestyle or running a company.

10 - Using Resources

Define finite (1 mark)

• Resources that are being used up faster than they can be replaced.

• These resources will eventually run out (e.g fossil fuels)

Define renewable (1 mark)

• Can be replaced at the same rate at which they are being used up.

• E.g. Crops grown to make biofuels and wood are examples of these types resources.

Define potable (1 mark)

• Water that is safe to drink

Describe and explain the stages involved in making saltwater/seawater potable – 2

methods (3 marks each)

• Desalination using distillation: • Heat the saltwater to evaporate the water,

leaving the salt behind. • Condense the water by cooling. • Collect freshwater and add chlorine to kill

bacteria

• Reverse osmosis • Apply pressure to saltwater • Force it through a semi-permeable

membrane, which will not let salt through • Collect freshwater and add chlorine to kill

bacteria

Define pure (1 mark)

1. A substance that contains one type of particle

2. e.g. Neon contains only Na atoms 3. e.g. Carbon dioxide contains only CO2

molecules

Describe and explain the stages involved in making freshwater potable (3 marks)

1. Filter to remove large particles 2. Add aluminium sulphate to cause smaller

particles to clump together 3. Filter through a sand bed 4. Add chlorine to kill bacteria and

microorgnisms

Evaluate the two methods of treating saltwater

Advantages of distillation: • Pure water at the end • Quick

Disadvantages of distillation:

• High energy cost Advantages of reverse osmosis:

• No heating, so lower energy cost than distillation

Disadvantages of reverse osmosis:

• Still some energy cost in applying pressure • Salt can erode the membrane over time so it

will need to be replaces • Process only removes 98 % of salt.

Describe and explain the stages involved in treating waste water (4 marks)

1. Filter to remove large impurities 2. Sedimentation to remove sludge 3. Biological treatment with bacteria to kill

microbes 4. Sedimentation to remove secondary sludge 5. (3 and 4 can be repeated) 6. Add chlorine to kill bacteria 7. Put water back into rivers

What is an ore? (1 mark)

A rock that contains enough metal to be extracted economically

What happens to the sludge produced in the treatment of waste water?

Pros:

• Dried to form a ‘cake’ which can be used as a fuel

• Can be used as a fertiliser Cons:

• Can go to landfill

Why can we not always treat freshwater (even though it is the simplest form of water

treatment?

• Some hot countries have a very limited supply of freshwater as it evaporates from lakes and reservoirs

• Seawater must be used instead.

What is phytomining and explain how it is used to extract copper?

Extraction of copper from contaminated ground containing low grade copper ore using plants.

• Plants are grown on land containing low grade copper ore.

• The plants absorb Cu2+ ions through their roots.

• The plants are burned, producing ash containing copper oxide (CuO)

• The ash is dissolved in sulphuric acid (H2SO4)

• The copper is extracted from the solution using electrolysis.

* remember it needs to be in solution so the ions can move!

What is the difference between low grade and high grade ore?

• High grade ore contains enough metal

oxide to extract the metal economically using reduction using carbon/smelting.

• Low grade ore only contains very small amounts of metal oxide – not enough to extract it profitably.

Explain how scrap iron can be used to extract

copper

• Iron is more reactive than copper • It will displace copper in a compound

leaving an iron compound and copper

e.g. 2Fe + 3CuO à 3Cu + Fe2O3

What is bioleaching explain how it is used to extract copper?

Extraction of copper from low grade ores using bacteria

• Bacteria is added to low grade ore and

absorb copper compounds • The bacteria produces a solution called a

leachate that contains copper ions.

Evaluate bioleaching and phytomining as methods of extracting copper (6 marks)

• Advantages are that both phytomining and

bioleaching can be used to extract Cu from low grade ores.

• Disadvantage is that both are slow. • Advantage is phytomining can be made

quicker by using fast growing plants • Advantage is phytomining can be used on

contaminated ground. • Advantage of bioleaching is it can be used

on waste from quarries. • Disadvantage of bioleaching is it produced

toxic chemicals that can flow into rivers.

What is an LCA?

• A Life Cycle Assessment • An assessment of the impact a product has

on the environment throughout its whole life

What are the 5 stages in a LCA?

• Raw materials • Production • Transportation • Product use • Disposal

What is a value judgement?

• A subjective opinion on the impact of a

process on the environment.

• e.g. We can quantify (objectively) the amount of CO2 released into the atmosphere. We cannot quantify (put a number on) the impact this has on the level of global warming/the effect it has on the atmosphere (subjective)

Evaluate the limits of LCAs (6 marks)

We can quantify: • How much water is used • How many resources are used • How much energy used • How much waste is produced This is objective and scientific We cannot quantify:

• The effect of pollutants on the atmosphere • The effect of extracting resources on the

environment We have to use value judgements These are subjective and based on opinion

• LCAs can be abbreviated to quote facts a company wants to advertise but leave out other facts. E.g. The product can be reused which is good for the environment, but leave out the fact the transportation of the product to shops causes global warming through burning fuels.

• LCAs need to be peer-reviewed in order to be trusted.

What is the importance of peer-reviewing in science?

• Allows scientific claims to be checked and

verified by someone not linked to the company.

• Removes bias.

What is corrosion? (1 mark) (triple only)

• The destruction of materials by chemical reactions with substances in the environment

What is rusting? (triple only)

• Iron that has been corroded by oxygen and water

• Rust = iron oxide, Fe2O3 How can rusting and corrosion be prevented (3

methods, with examples) (triple only)

1. Painting or greasing – protects the surface of the metal from oxygen and water

2. Sacrificial protection – coat with a more reactive metal that will react with oxygen and water over the metal being protected. E.g. Magnesium is used as sacrificial protection on steel ships.

3. Oxide coating – the metal reacts with oxygen to form a protective, unreactive metal oxide coating. Eg aluminium forms an oxide coating itself.

What is an alloy and why are they used? (3 marks) (triple only)

• A mixture of elements, one of which is a

metal • Alloys are stronger than pure metals (which

are soft *Link to structure and bonding: the layers in alloys are disrupted and cannot slide, whereas in pure metals, layers of atoms can slide.

How is soda-lime glass made?

• Heating a mixture of sand, sodium carbonate and limestone.

How is borosilicate glass made?

• Sand and boron trioxide • Melts at higher temperatures than soda-

lime glass

What is a composite and how are they made? (triple only)

• Two materials • A matrix or binder surrounding • Binding together fibres or fragments of the

other material, which is called the reinforcement

Where do the raw materials come from in the Haber process? (2 marks) (triple only)

N2 + 3H2 2NH3

• Nitrogen from the air • Hydrogen from natural gas (fossil fuels)

How are clays ceramics made?

• shaping wet clay • heating in a furnace • e.g. pottery and bricks

What are the compromise conditions used in the Haber process? (3 marks) (triple only)

• 450 oC • 200atm • Fe catalyst

Explain how to maximise the yield of ammonia in the Haber process – what are the optimum conditions and why? (6 marks) (triple only)

N2 + 3H2 2NH3 ΔH = -92kJ/mol

• High pressure will favour a high yield of

ammonia • This is because there are 4 moles on the left

and 2 on the right. • Increasing the pressure will cause the

equilibrium to shift to the right to try and reduce the pressure

• Low temperature will favour a high yield of

ammonia. • This is because the forward reaction is

exothermic. • Lowering the temperature will cause the

equilibrium to shift to the right in the exothermic direction to try and increase the temperature.

Describe how ammonia is made in the Haber Process

• Nitrogen and hydrogen react under at 450

oC and 200 atm over a high surface area Fe catalyst

• The mixture is cooled and ammonia condenses and is removed.

• Nitrogen and hydrogen gas are recycled back into the reactor.

Explain why compromise conditions are needed in the Haber Process (4 marks) (triple only)

• Optimum low temperature would cause a

very slow rate. • Optimum high pressure would be expensive

and pose a safety risk. • Compromise conditions allow a reasonable

yield to be produced at a reasonable rate • The Fe catalyst causes equilibrium to be

reached more quickly.

What elements are found in fertilisers?

• Nitrogen – N • Phosphorus – P • Potassium – K

(Fertilisers are formulations)

Describe how NPK fertilisers are made

• Potassium chloride, potassium sulfafe and phosphate rock are obtained by mining, but phosphate rock cannot be used directly as a fertiliser.

• Phosphate rock is treated with nitric acid or sulfuric acid to produce soluble salts that can be used as fertilisers.

Required Practicals

Practical Activity 1

Preparation of a pure, dry sample of a soluble salt from an insoluble oxide or carbonate, using a Bunsen burner to heat dilute acid and a water bath or electric heater to evaporate the solution.

Practical Activity 2 (Triple only)

Determination of the reacting volumes of solutions of a strong acid and a strong alkali by titration.

Determination of the concentration of one of the solutions in mol/dm3 and g/dm3 from the reactive volumes and known concentration of the other solution


Investigate what happens when aqueous solutions are electrolysed using inert electrodes. This should be an investigation involving developing a hypothesis


Investigate the variables that affect temperature changes in reacting solutions such as, eg acid plus metals, acid plus carbonates, neutralisations, displacement of metals


Investigate how changes in concentration affect the rates of reactions by a method involving measuring the volume of a gas produced and a method involving a change in colour or turbidity. This should be an investigation involving developing a hypothesis.


Investigate how paper chromatography can be used to separate and tell the difference between coloured substances. Substances should be able to calculate Rf values.

Practical Activity 7 (Triple only)

Use of chemical tests to identify the ions in unknown single ionic compounds covering the ions from sections Flame tests through to Sulfates


Analysis and purification of water samples from different sources, including pH, dissolved solids and distillation

1 - Atomic Structure and the Periodic Table...1 - Atomic Structure and the Periodic Table Describe the structure of an atom. • Atoms contain a nucleus (made of protons and neutrons)

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