138081912-All-Revision

RATES OF REACTION The rate of a chemical reaction is determined by HOW FAST a reaction occurs (this is the rate of reaction):

TYPES OF REACTION : VERY FAST – an explosion e.g. dynamite

FAST – group 1 metals + water

SLOW – zinc + acid

VERY SLOW – rusting

FACTORS AFFECTING RATE: TEMPERATURE: each atom will then have a higher kinetic energy, which increases the number of collisions (as the particles are moving faster and crazier), and bigger and faster collisions

CONCENTRATION: a higher concentration means more atoms and molecules – which will then increase the

probability of collision, which increases the efficiency of a reaction

SURFACE AREA: the larger the surface area, the more reactions can take place on that certain substance,

which increases the efficiency of the reaction

CATALYST: lowers the ACTIVATION ENERGY allowing the substance to react at a lower temperature, which decreases the amount of energy needed, allowing it to react faster

PRESSURE: the increase in pressure for gases is the same as increasing concentration for liquids; it means

that there are more of that certain atom, which therefore increases the likelihood of collision

CATALYSTS They are mainly used in industrial processes, as they manage to speed up the rate of reaction. They do this by lowering the activation energy, which means that they can use less energy to complete the reaction. This reduces costs, and is therefore very useful to the companies.

ENZYMES Enzymes are complex molecules which act as a biological catalyst in leaving systems, such as humans (amylase, protease etc.). They are very sensitive to temperature and pH.

Catalysts Enzymes

Manganese Dioxide – Making O2 from hydrogen peroxide

Amylase

Platinum, Rhodium & Palladium – used in car exhaust pipes

Protease

Nickel - making margarine Lipase

ATOMIC STRUCTURE &

CHEMICAL BONDING

Electrons:

relative charge: -1 relative mass: 1

1836

Protons

relative charge: +1 relative mass: 1

Neutrons

relative charge: 0 relative mass: 1

Electrons found in a shell around the nucleus

Nucleus has protons and neutrons

POTASSIUM’S ELECTRONIC STRUCTURE

Atoms transfer electrons in chemical bonds to try and achieve a full outer shell – as it is MORE STABLE.

IONS Ions are electrically atoms or groups of atoms. They are formed by the loss or gain of electrons

Type of Ion Charge

Metal Atoms&Ions Positively Charged (+)

Non-Metal Ion Negatively Charged (-)

COMMON IONS SODIUM: Na+ MAGNESIUM: Mg2+ AMMONIUM: NH4

+ OXIDE: O2- CHLORIDE: Cl-

IONIC BONDING Ionic bonding includes the gain or loss of one or more electrons from an atom

-to obtain a FULL OUTER SHELL

Ionic Bonding only occurs between: METALS AND NON-METALS (1metal+1non-metal)

K 2,8,8,1

EXAMPLES:

Cl Na

Na Cl

NaCl

O Mg

Mg O

MgO

LATTICE STRUCTURE A way of displaying regular patterns within atoms of oppositely charged ions is used a lattice structure:

IONIC SUBSTANCES THEY HAVE HIGH METING POINTS: strong electrostatic bonds between each ion (and these have to

break) o The greater the charge on the ions – the higher the melting and boiling point.

COVALENT BONDING DEFINITION: Covalent bonding is the sharing of a pair of electrons between two atoms. Covalent bonds are only

formed between NON-METALS + NON-METALS.

F Al

Al F

AlF3

Lattice of NaCl +

+ +

+ + +

+ + - -

- -

-

- -

FORMATION

METALLIC BONDING

DEFINITION A metallic bond is a giant structure of positive (metal) ions, surrounded by a sea of delocalised (free) electrons.

Cl Cl H H H Cl

O O

H

O

H H

C

H

H

N

H

H

O O O

Positive metal ions

‘Sea’ of negative ions

+

+ + + +

+

+

+

STRUCTURE CARBON DIOXIDE :

•Double bonds •Structured in a line •It is stable (has a full outer shell)

DIAMOND

Single covalent Bonds All bonds are strong No weak Bonds Tetrahedron of Carbon atoms

GRAPHITE Hexagonal shape of c atoms Only 3 covalent bonds It is formed in layers Weak bonds between layers

C O C

C

C

C C

C

C

THE STRUCTURE DIAGRAM

SIMPLE MOLECULAR SUBSTANCES They normally have low boiling and melting points because the forces of attraction are typically weaker, and therefore they are easier to break.

They don’t conduct electricity, because they are all COVALENT bonds, and therefore share electrons – which

UTILISES all of them, which means there are no free electrons.

DIAMOND and GRAPHITE have many strong covalent bonds – making their melting and boiling points very high.

HOWEVER DIAMOND has no free electrons within its structure which means that it cannot conduct electricity.

GRAPHITE does have free electrons between layers of carbon atoms, and can therefore conduct

electricity. It also has layers of carbon atoms connected by weak bonds making them slippery.

Giant Structure Molecular Structure

Substances made up of huge numbers of atoms, or ions

Substances that are made up of a mixed number of atoms shown by the molecular formula (eg. H2O or

C6H12O6

The number of particles is not fixed, but are usually arranged in a regular pattern (lattice)

Generally the atoms are joined by covalent bonds. The molecules are usually very small but can be

large in some cases

Includes:

Giant Metallic - all metals and alloys Giant ionic – all ionic substances

Giant Covalent – in diamond, graphite and silicon

Includes Simple Structures:

Monatomic – like He, Ne, Ar etc. Simple Molecules – like H2, H2O, CO2

Structure

Simple Giant

Graphite Diamond

Silicon

Carbon

All Metals

Anything Ionic Almost all

covalent substances

MACROMOLECULE A macromolecule is an extremely large molecule containing a very large number of atoms.

REACTIVITY SERIES

DISPLACEMENT Example:

OXIDE: The removal of electrons from a substance, or the addition of oxygen

REDUCTION: The addition of electrons from a substance, or the removal of oxygen

REDOX: a reaction in which reduction and oxidation is both occurring

OXIDISING AGENT: A substance that is capable of oxidising another substance

REDUCING AGENT: A substance that is capable of reducing another substance

Element Cold water/steam Dilute Acid

Potassium

React very vigorously with cold water to form a solution of the metal

hydroxide + hydrogen

Reacts vigorously to form a metal salt + hydrogen

Sodium

Lithium

Calcium

Decreasing vigour as scale decreases (forms metal salt +

hydrogen)

Magnesium Reacts very slowly with cold water, but burns with steam → MgO + H2

Aluminium Does not react with cold water however reacts with steam without burning, to form metal oxide +

hydrogen

Zinc

Iron

Tin

Does not react with steam or water

Lead

Copper

Does not react Silver

Gold

Platinum

More reactive

Take Salt

EXAMPLES 2Na+O→ Na2O

Mg + O → MgO

2K + 2H2O → H2+2KOH

Ca + 2H2O → Ca(OH)2 + H2

3AgNO3 + Fe → 3Ag + Fe(NO3)3

MgSO4 + Cu → CuSO4 + Mg

RUSTING Fe2 + 3O2 → Fe2O3

A REDOX reaction will occur and the iron will be oxidised. Rusting normally occurs in moisture-prone areas.

EXTRACTION & USES OF METALS Most metals found recently are higher up in the reactivity series. This is because as technology progresses we are able to find more reactive substances, which could not have been found previously, and so are now founded.

As the reactivity series increases the extraction methods become more extravagant and expensive.

If the substance is low down it is safer and can therefore be used in consumer products.

QUALITATIVE ANALYSIS Qualitative: what is present?

Quantative: how much?

IONS An ion is a charged atom or molecule: Cations are POSITIVE: Li+, Na+, K+, and NH4

Anions are NEGATIVE: F-, Cl-, Br-, and OH-

Ions can have more than one charge however.

Group 1 2 3 4 5 6 7

Charge +1 +2 +3 -3 -2 -1

Positive Ions Negative Ions

Hydrogen ion H+ Magnesium Mg2+ Aluminium Al3+ Chloride Cl- Oxide O2-

Lithium Li+ Calcium Ca2+ Iron(III) Fe3+ Bromide Br- Co32-

Sodium Na+ Barium Ba2+ Iodide I- Sulfate SO42-

Potassium K+ Manganese (II) Mn2+ Hydroxide OH-

Ammonium NH4+ Iron (II) Fe2+ Nitrate NO3-

Copper (II) Cu2+

Zinc Zn2+

TESTING FOR CATIONS 1. Flame test: some metals burn with a distinctive colour 2. Dissolve the unknown substance in concentrated Hydrochloric Acid (HCl) 3. Dip this solution on a piece of sterile wire 4. Hold in a hot flame

Metal Ion Flame Colour

Li+ (Lithium) Red – scarlet

Na+ (Sodium) Orange – yellow

K+ (Potassium) Lilac

Ca2+ (Calcium) Brick-red

Ba2+ (Barium) Apple-Green

Or

1. Sodium Hydroxide test: adding sodium hydroxide to Cations produces a precipitate 2. Aqueous metal salt + aqueous sodium hydroxide precipitate

Metal Ion Precipitate

Al3+, Mg2+, Ca2+ White precipitate

Al(OH)3 Re-dissolves sodium

hydroxide

Cu2+ Pale blue

Fe2+ Dirty green

Fe3+ Rusty brown

SYMBOL EQUATION: CaCl2 (aq)+2NaOH(aq) →Ca(OH)2 (s)+2NaCl(aq)

IONIC EQUATION: Ca2+(aq) + 2OH-(aq) Ca(OH)2 (s)

TESTING FOR IONS The anions are only the halides (group 7 metals – Cl, Br, I), the sulphates, carbonates, and nitrates.

HALIDES: You can test for them using DILUTE NITRIC ACID AND SILVER NITRATE forms an insoluble silver iodide precipitate.

1. Make a solution of suspected halide 2. Add enough nitric acid to make it acidic 3. Then add some silver nitrate solution (AgNO3 (aq))

White precipitate: AgCl

Pale Green: AgBr

Yellow: AgI

Equations Ag+

(aq) + X-(aq) AgX (s)

Ag+(aq) + Cl-

(aq) AgCl (s)

AgNO3(aq) + NaBr(aq) AgBr NaNO3 (s)

As the precipitates are similar colours you can do a further test to make sure that you know what is what.

The test is the SOLUBILITY IN AMMONIA SOLUTION.

Halide Solubility in Dilute Ammonia In Concentrated Ammonia

Silver Chloride

Silver Bromide

Silver Iodide

FURTHER ATOMIC STRUCTURE

A Single Atom

2 Separate Atoms

2 Chemically Joined Atoms

GENERAL STRUCTURE

Isotope: atoms with different numbers of neutrons however, are the same element.

Relative atomic mass: the weighted average mass of the isotopes of an element relative to an atom of Carbon-12

We use the weighted average mass because there AREN’T EQUAL AMOUNTS OF ISOTOPES of each

element.

To find out the Relative Formula Mass (Mr) of Chlorines isotopes, we need to know its isotopes and their relative atomic mass:

Eg1. The isotopes of chlorine are: 75% 35Cl, and 25% 37Cl.

When we add these two together, we get 35.5, this means the RFM (Mr) is 35.5 (35.5Cl)

Relative Formula Mass: the relative formula mass of a compound is the sum of relative atomic masses (Ar) of the atoms in the numbers shown in the formula.

Eg2. MgCO3= 1 Mg 1 C 3 O

( )

23

11 Na

Mass Number – protons and neutrons

Atomic Number – Protons (and neutrons if it isn’t an isotope)

Mass

Mr Mole

THE MOLE The mole is a measurement of a substance, a ‘mole of carbon’; ‘a mole of water’.

For example: Ar of C=12 . . . So 1 mole of C is 12g

Mr of H2O is 18, so 1 mole of H2O is 18g

The molar mass = mass of 1 mole

= same as Mr

QUESTIONS What’s the mass of 1 mole of Mg?

Ar=24.3, 1 mole=24.3g

What is the mass of 1 mole of NaOH?

Mr=40, 1 mole=40g

What is the mass of 0.2 moles of CaCO3?

Mr=100, 0.2x100=20g

How many Moles in 54g of H2O?

Mr=18,

18 moles

AVOGADRO’S NUMBER One mole of something always contains the same number of molecules (or atoms if it’s an element) That number is 3 So 1 mole of carbon has a mass of 12g and contains 3 atoms of Carbon-12 But 1 mole of water has a mass of 18g and also contains 3 of water molecules

KEY CONCEPTS Radicals Formula Valency

Ammonium NH4 - 1

Hydroxide OH- 1 Nitrate NO3

- 1 Carbonate CO3

2- 2 Sulfate SO4

2- 2

The reaction ratio is called the STOICHIOMETRY

GENERAL FORMULAS

CALCULATIONS WHAT MASS OF MGO IS FORMED WHEN 4.8G OF MG IS OXIDISED?

1. Balance Equation:

2. Stoichiometry:

3. Work something out:

4. Mr of MgO = 40

PERCENTAGE YIELD

EMPIRICAL FORMULA 1. Calculate moles of each element 2. Divide by smallest = ratio

Eg1. Mg O Eg2. H O

=0.1

1

1

8

16

0.1

MgO H2O

AVOGADRO’S LAW That 1 mole of any gas will OCCUPY 24DM

3

1Litre = 1dm3 = 1000cm3 1 Mole of Ammonium will occupy 24000cm3

CALCULATING THE VOLUME OF GAS CALCULATE THE VOLUME OF 0.01G OF HYDROGEN:

3

CALCULATE THE VOLUME OF CARBON DIOXIDE PRODUCED AT ROOM TEMPERATURE WHEN DILUTE

HCL IS ADDED TO 1.00G OF CACO3

3

CALCULATING THE CONCENTRATION This is the number of moles in a litre (of water or another solvent)

1mole in litre has a concentration of 1mol/dm3 (1moldm-3)

Also 1M = 1 molar solution

Volume in dm3

𝑀𝑜𝑙𝑒𝑠 𝑚𝑎𝑠𝑠

𝑀𝑟

𝑚𝑜𝑙 𝑔𝑎𝑠 𝑑𝑚3

𝑐𝑚3

CRITICAL EQUATIONS :

CHEMISTRY OF THE ELEMENTS IMPORTANT GROUPS :

Group 1 – LITHIUM, SODIUM, POTASSIUM

Group 7 – CHLORINE, BROMINE, IODINE

Group 0 – noble gases; HELIUM, NEON, ARGON (full outer shell)

GROUP 1 In group 1, the elements get INCREASINGLY REACTIVE due to the distance between the first shell and last

shell, in order for a reaction to take place, these shells must be broken, and so the more that need to be broken, the more reactive they are.

GROUP 7 Chlorine – a yellow/green GAS at room temperature

Bromine – a brown LIQUID at room temperature

Iodine – a black SOLID at room temperature

ORGANIC CHEMISTRY

Term Definition

Homologous series A series of organic compounds that have the same general formula, similar chemical reactions and where each member differs from the

next by a –Ch2- group

Hydrocarbon A compound only containing the elements hydrogen and carbon

Saturated An organic compound in which all bonds are single bonds

Unsaturated An organic compound that contains carbon-carbon double bonds

General Formula A formula that states the ratio of atoms of each element in the formula of every compound in a particular homologous series

Isomerism Compounds that have the same molecular formula but different displayed formulae are said to exhibit isomerism; the different

compounds are called isomers

ALKANES This is a homologous series that has the general formula: CnH2n+2 . these are the first five terms in the

series:

Molecular Formula Name

CH4 Methane

C2H6 Ethane

C3H8 Propane

C4H10 Butane

C5H12 Pentane

Displayed Formula

Reactions Combustion: the alkane’s burn when heated in air or oxygen. If there is a plentiful supply of air/oxygen the products are carbon dioxide and water.

( ) ( ) ( ) ( )

3 8 ( ) ( ) ( ) ( )

Methane Ethane Propane Butane

Dimethylpropane Methylbutane Methylpropane Pentane

Both butane and pentane have isomers: Methylpropane is an isomer of butane; and Methylbutane and Dimethylpropane

are isomers of pentane

If there is insufficient oxygen:

( ) ( ) ( ) ( )

With Bromine: Methane and bromine react together in the presence of UV radiation to form bromomethane.

( ) ( ) 3 ( ) ( )

ALKENES This is a homologous series that has the general formula: CnH2n. these are the first five terms in the series:

Molecular Formula Name

C2H4 Ethene

C3H6 Propene

C4H8 Butene

C5H10 Pentene

Reactions of the Alkenes Alkenes undergo addition reactions with halogens. For example, a bromine molecule will add across the double bond of ethene to form 1,2-dibromoethane:

1,2-dibromoethane is colourless, so when bromine or bromine water is shaken with ethene

the BROMINE WILL DECOLOURISE. All alkenes will

decolourise bromine. This is the TEST FOR

UNSATURATION (c=c double bonds).

Ethene Propene But-1-ene

Methylpropene Methane Ethane Propane Butane

But-2-ane Methane Ethane Propane Butane

ETHANOL Ethanol is manufactured by two different processes: fermentation and direct hydration of ethane.

Fermentation Dissolve sugar or starch in water and add yeast Leave the mixture to ferment at 25-40ᵒC for several days in the absence of air Filter off the excess yeast to obtain a dilute solution of ethanol

If the ethanol content in the mixture rises to around 15%, the yeast is now killed. If a more concentrated solution of ethanol is required, the mixture is fractionally distilled. Whatever the starting point, sugar or starch, the enzymes in the yeast produce glucose, C6H12O6. The enzymes in yeast then convert the glucose into ethanol:

6 1 6( ) ( ) ( )

Direct Hydration of Ethane A mixture of ethene and steam is passed over a phosphoric acid catalyst at a temperature of 300ᵒC

and 60-70 atmosphere pressure: ( ) ( ) ( )

The ethanol is condensed as a liquid The ethene required for this reaction is obtained from crude oil

Comparing the Two Methods

EXTRACTION OF ALUMINIUM The method of extraction of metals relates to their reactivity, the higher the reactivity, the more difficult the extraction process.

Fermentation Hydration

Raw materials USE RENEWABLE SOURCES Uses NON-RENEWABLE resources –

once all the crude oil is used up there will not be any more

Type of process BATCH process CONTINUOUS process

Rate of reaction Very SLOW, several days FAST

Quality of product

Produces a DILUTE solution of ethanol that needs further

processing if pure ethanol is required

Produces PURE ETHANOL

Reaction conditions LOW TEMPERATURES required High temperature and pressures

required, increasing the COSTS

ELECTROLYSIS

The positive and negative electrodes are made of graphite (Carbon). The electrolyte is a solution of aluminium oxide dissolved in molten cryolite. The main ore of aluminium is bauxite. The bauxite is first purified to produce aluminium oxide, Al2O3 Aluminium oxide has a very high melting point and hence it is dissolved in cryolite to make the

electrolyte. This mixture has a much lower melting point and is also a much better conductor of electricity than molten aluminium oxide.

At the negative electrode: 3

The aluminium melts and collects at the bottom of the cell and is then tapped off.

At the positive electrode:

Some of the oxygen produced at the positive electrode then reacts with graphite to produce carbon dioxide gas:

( ) ( ) ( )

This means that the positive electrode slowly burns away and needs to be regularly replaced.

+ -

Positive electrode

Negative electrode

Insulation

Electrolyte

Tapping hole

EXTRACTION OF IRON BLAST FURNACE

The raw materials are iron ore (haematite), coke (carbon), limestone (calcium carbonate) and air

Iron ore, coke and limestone are mixed up together and fed into the top of the blast furnace

Hot air is blasted into the bottom of the furnace

Iron ore mixed with limestone and coke

Waste gases

Waste gases

Blast of hot air

Molten slag

Molten iron

THE REACTIONS

Oxygen in the air reacts with the coke to form CARBON DIOXIDE:

( ) ( )

Carbon dioxide reacts with coke to form CARBON MONOXIDE:

( ) ( ) ( )

Carbon monoxide REDUCES IRON (III) OXIDE in the iron ore:

3( ) ( )

The iron melts and collects at the bottom of the furnace, where it is tapped off

The calcium carbonate in the limestone decomposes to form CALCIUM OXIDE:

3( ) ( ) ( )

The calcium core reacts with silicon dioxide, which is an impurity in the iron ore, to form CALCIUM

SILICATE:

( ) ( ) 3( )

The calcium silicate melts and collects as a molten slag on top of the molten iron, which is then

tapped off separately

USES OF ALUMINIUM AND IRON Aluminium

Iron

Use Most important property

Aeroplane body high strength-to-weight ratio

Overhead power cable Good conductor of electricity

Saucepans Good Conductor of heat

Food cans Non-toxic

Window frames Resists corrosion

Use Most important property

Car Bodies Strong (withstand collisions)

Iron Nails Strong

Ships, Girders & Bridges Strong

CRUDE OIL WHAT IS IT? Crude oil is a thick, sticky, black liquid that is found under the ground and under the sea in certain

parts of the world such as the Middle East and Texas (USA). It is a mixture of hydrocarbons, MOSTLY

ALKANES.

REFINING CRUDE OIL Crude oil, as such, has no direct use. It has to BE REFINED before it is of any use. The first step in the

refining of crude oil is FRACTIONAL DISTILLATION.

Fractional distillation is carried out in fractioning columns. The column is hot at the bottom and gradually becomes cooler towards the top.

The crude oil is split into various fractions as described below. A fraction is a mixture of hydrocarbons with very similar boiling points.

Crude oil is heated to convert it into VAPOUR and is then fed into the bottom of the column

The hydrocarbons with very high boiling points (fuel oil and bitumen) IMMEDIATELY TURN INTO LIQUIDS and are tapped off at the bottom of the column

The hydrocarbons that have boiling points lower than 400oC remain as gases and RISE UP THE COLUMN, AS THEY DO THEY COOL DOWN.

The different fractions will condense at different heights according to their different boiling points. When they condense they are tapped off as liquids

The fraction with the lowest boiling point (refinery gas) REMAINS AS A

GAS and comes out the top.

Refinery gases

Gasoline (petrol)

Kerosene

Diesel Gas (gas oil)

Fuel Oil

Bitumen

Crude Oil

40oC

400oC

Fractioning Column

PROPERTIES

USES

HOW DOES CRACKING WORK? Alkane is a long-chain hydrocarbon, and these molecules are passed over a catalyst (silica or aluminium oxide) and heated to about 600oC. They then start to break down into a short-chained alkane, and at least one alkene.

Eg. Cracking of Decane (C10H22) to produce octane (C8H18) and ethene (C2H4).

1 ( ) 8 18( ) ( )

INCOMPLETE COMBUSTION can create carbon monoxide, which reduces the bloods ability to carry oxygen.

Fraction Number of

Carbon Atoms Boiling Point Thickness

Refinery Gases

INCREASES

INCREASES

INCREASES

Gasoline

Kerosene

Diesel Oil

Fuel Oil

Bitumen

Fraction Uses

Refinery Gases Bottled Gas For Camping

Gasoline Petrol for Cars

Kerosene Fuel for planes; oil for central heating; paraffin for small heaters

Diesel Oil Diesel fuel for buses, lorries, trains and cars

Fuel Oil Fuel for ships and for industrial heating

Bitumen Road surfaces and covering flat roofs of buildings

OXYGEN AND OXIDES COMPOSITION OF GASES IN CLEAN UNPOLLUTED AIR :

HOW TO SHOW THAT AIR CONTAINS 1

OF OXYGEN : TH

Using Copper

This apparatus can be used to find the percentage of oxygen in air:

Set up the apparatus with 100cm3 of air in one gas syringe

Heat the copper at one end of the silica tube using a blue Bunsen burner

Pass the air backwards and forwards over the copper

As the volume of gas decreases, move the Bunsen flame along the tube so it heats fresh copper

Stop heating when the volume of gas has stopped decreasing

The copper has reacted with the oxygen to form black copper oxide:

( ) ( ) ( )

The final volume will be around 78-79cm3 which shows that 21cm3 has reacted with the copper – so

that says that 21% of oxygen is in the air.

Gas Percentage in Air

Nitrogen 78

Oxygen 21

Argon 0.9

Carbon dioxide 0.04

Originally 100cm3 of air Silica tube packed with copper

Gas syringe Heat

Using Iron Place wet iron filings in the end of a burette and set up the apparatus as shown in the diagram. Over several days the water will rise up the burette and reach a constant level. This is because the iron reacts with the oxygen in the air. Take the initial and final readings of the water level in the burette.

( )

( )

( )

LABORATORY PREPARATION OF OXYGEN Hydrogen peroxide (H2O2), decomposes slowly to form water and oxygen. The speed of decomposition is increased by adding a catalyst: MnO2, manganese dioxide. The oxygen can be collected over water. Since oxygen is not very soluble in water, very little is lost. An aqueous solution of hydrogen peroxide is used.

( ) ( ) ( )

Manganese (IV) Oxide

Oxygen

Hydrogen Peroxide

REACTIONS OF OXYGEN

Magnesium oxide is a basic oxide, and is very slightly soluble in water and when saturated will have a pH of about 10. It reacts with water to form magnesium hydroxide:

( ) ( ) ( ) ( )

CARBON DIOXIDE LAB PREPARATION: 3

The reaction between any metal carbonate and an acid will produce carbon dioxide. Calcium carbonate is the most commonly used carbonate in the laboratory preparation of carbon dioxide. The most convenient form of calcium is in marble chips. They are very easy to handle and the reaction is not too fast so the carbon dioxide is produced at a rate that makes it easy to collect. It’s not very soluble, little is lost.

Element Observations Equation

Magnesium Burns with bright, white flame to

form a white powder

Carbon Burns with a yellow-orange flame

to form a colourless gas

Sulphur Burns with a blue flame to form a

colourless gas

Calcium carbonate

Carbon Dioxide

Dilute Hydrochloric acid

Water