y 12 Periodicity

Y12 SL Starter:

(a) Decide on the type of INTRA and INTERmolecular forces present in the followingmolecules(b) Suggest bond angles and shape

1. Br202. Magnesium alloy3. Aluminium Oxide4. Hydrogen Sulphide5. Tribromomethane6. Compare and explain the difference in

atomic size between Na and Si7. Why are metals................metals ?

Periodicity

Group number is the number of valenceelectrons, or the number of electrons in theouter shell.

Going across a period is adding electrons tothe SAME shell.

http://liakatas.org/chemblog/wp-content/uploads/2008/09/periodic-table_properties-trends.gif

Trends in Periodic Table onto blanks withreasons - atomic radius, ionic radius,electronegativity, melting point HOMEWORK- with reasons

Definitions

First Ionisation Energy is the energyrequired to remove 1 mole of electrons froma gaseous atom to make 1 mole of ions : -

Electronegativity : Is the ability of an atom tohold onto a bonding pair of electrons IBdefinition ( desire of an atom to hold onto abonding electron pair - textbook

3.3.1

Write balanced chemical equations for thereactions of the first 3 alkali metals with(a) water.

(b) Chlorine, Bromine, Iodine.Experiment - Displacement of the halogensNB The most reactive ends up as the ion :-

Bromine+IodideBromide+Iodinered/browncolourlesscolourlesssilvery

fluoride+ChlorineNORXN

chloride+BromineNORXN

Use blog resources to review todays lesson

Y12 SL Formative Questions - completed with 12-6 students

1. Write equations (it is important to show all statesymbols in these equations) showing how sodium andmagnesium dissolve in water.2Na+2H20 2NaOH+ H2Mg+2H20 Mg(OH)2 + H2

2. What is the pH of the resulting solution?More than 7 ( 8-14 )

3. What type of bonding is present in these metal oxidesand how does this affect the melting points of theseoxides?ionic bond, high melting point

4. Will aluminium and silicon dioxide dissolve in water?Does not react as Al and Si oxides are polar covalent

molecules, their bonds are too strong to be overcome by thedissociated water molecules.

5. Aluminium oxide is said to be amphoteric. Explainwhat this means and give equations to illustrate youranswer.

reacts with both acid and alkalie.g. Acid + Metal Salt + HydrogenAcid + Base Salt + WaterAcid + Carbonate Salt + Water + Carbon Dioxide

6. Silicon dioxide has a very high melting point. Explainthis in terms of the bonding and structure of thiscompound.giant covalent structure, ( ref: graphite, diamond )

[different value of conductivity]7. Phosphorus oxide is more commonly found as P4O10.

Write an equation showing how it dissolves in water.(HL ONLY)P4O10+ 6H20 4H3PO4

8. Would the resulting solution by acidic, basic orneutral?

ACIDIC9. Sulfur oxide can exist as SO2 or SO3. Explain how

either of these can dissolve in water to give an acidicsolution.SO3 + H20 H2SO4

10. Chloro oxides are most conveniently written as

Cl2O7. Write an equation showing how it dissolves inwater. (HL ONLY)Cl2 + 7H20 Cl2O7 +7H2

11. Explain how the bonding of the oxides ofphosphorus, sulfer and chlorine affect their meltingpoints.

increasingly COVALENT so m.p. gets LOWER

12. Devise a trend in the chemistry of the period 3elements by relating their pH to their bonding andstructure.

Y12 AHL Starter:

(a) Decide on the type of INTRA and INTERmolecular forces present in the followingmolecules

(b) Suggest bond angles and shape

1. Carbon Disulphide2. Methanoic Acid3. Hydrogen Fluoride4. Tetraiodomethane5. 1,2 - dibromoethene6. Compare and explain the difference in

atomic size between atom of Na and anatom of Si.

7. Why are metals................metals ?

Periodicity

Group number is the number of valenceelectrons, or the number of electrons in theouter shell.

Going across a period is adding electrons tothe SAME shell.

Definitions

First Ionisation Energy is the energyrequired to remove 1 mole of electrons froma gaseous atom to make 1 mole of ions : -

Electronegativity : Is the ability of an atom tohold onto a bonding pair of electrons IB

definition ( desire of an atom to hold onto abonding electron pair - textbook

Mark Scheme :)

3.3.1

Write balanced chemical equations for thereactions of the first 3 alkali metals with(a) water.(b) Chlorine, Bromine, Iodine.

Experiment - Displacement of the halogens

Psst paper question - M07/4 Q.8 Review

w/c 3/12/12

Syllabus targets : 3.3.2, 13.1, 13.2

Starter : Which is the larger and why ?1. Na or Chlorine ATOM2. Caesium or Sodium ION3. Nitrogen or Sulphur ATOM4. Magnesium or Aluminium ION5. Chloride + KBr = ?

Objectives : 3.3.2 - ( Starting our tour ofPeriod 3 )+

Discuss the changes in nature, from ionic to covalent andfrom basic to acidic, of the oxides across period 3.

the solution becomes more acidic since the negative ionare able to bind with ____ and _____ leaving spare ____ ions.

What is hydrolysis : The reactivity of a substance when it isdissolved in water.

Practical to illuminate the real reactivity of Aluminium

Mercury Chloride is TOXICSodium Hydroxide is CORROSIVE

Return the Al to the NaOH solution as it will continue toexothermically react.DO NOT put any Hg waste down the sink.

Class conduct practical

Lesson 5 Transition Metals

Characteristics : High melting point, catalytic behaviour,coloured solutions ( complexes ), partially filled d orbitals,variable oxidation state.

Reflections :- M06/4/CHEMI/SP2/ENG/TZ0/XX

Lesson 6

Ligands and Complexes - please read this in anticipation ofnext lesson

View blog ppt presentation ( posted now )

Reactions of Chlorides with water

Reactions of Oxides with water

Check this

Make notes on:

1. Complexes Definition: Reversible associations of particles

(molecules, ions or atoms) through weak non-covalentbonds ( dative )

Metal complexes(a.k.a coordination compounds): Made of central metal atom or ion surrounded by

multiple anions or molecules with lone electronpairs or a formal -ve charge

Ligands joined to metal centres are said tocoordinate with each other, at coordinationsites

Usually interactions between s and p orbitals ofthe ligands and the d(or f) orbitals of the metalcentre

The act of binding is called chelation (CRAB) Naming complexes:

Write ligand name in alphabetical order Add prefix which gives an idea of number of

coordination site Anions end in o Most neutral ligands keep their name, except NH3

becomes ammine; H2O becomes aqua; CObecomes carbonyl.

Add name of central metal/ion eg:

[NiCl4]2- tetrachloronickelate (II) ion [CuNH3Cl5]3-

amminepentachlorocuprate(II) ion [Cd(en)2(CN)2]

dicyanobisethylenediaminecadmium(II)

2. Ligand Definition: a ligand is an atom, ion or functional group

that is bonded to one or more central atoms or ions,usually metals generally through co-ordinate covalentbond.1

Definition: An ion or molecule attached to a metalatom by coordinate bonding.

Ligand geometry : Characterized by placing the central(usually metal) atom in the middle of a polyhedron.Eg, Tetrahedral structure with one central atom andfour regularly distributed ligands.

Types of ligands : monodentate and polydentate.i) Monodentate - ligands that bind through onesite (mono = one) (monodentate are IB /multidentate are not NOT EDTA)ii) Polydentate - ligands that bind through morethan one site (poly = many) due to extra lone pair

1

"Ligand."ChemistryDaily.Wikipedia.org,1Apr.2007.Web.6Dec.2012..

of electrons.iii) chelated complexes - complexes of polydentateiv) scorpionate ligand - ligand that binds throughthree sites.

Examples of ligands: Benzene, F_ , Br_, Cl_, I_, CO_, OH_

Examples of monodentate and bidentate ligands.

3. Why Sc and Zn are not considered transition metalsIUPAC definition : an element whose atom has anincomplete d sub-shell, or which can give rise to cations withan incomplete d sub-shell.2

Sc does not have variable oxidation states, as its electron 2

configuration is [Ar]4s23d1. It can only form +2 ions as it isnot energetically efficient to lose only one electron in the sorbital.

Zn has fully filled d-orbitals, which means it does not countas a transition metal as transition metals make use ofpartially-filled d-orbitals.

4. Explain coloured complexesWhen white light passes through a solution of d-blockelements, or is reflected off it, some colours of lights areabsorbed, and the colour we see is what the eyes perceiveto be left.

2Nic,M.Jirat,J.Kosata,B.,eds.(2006)."transitionelement".IUPACCompendiumofChemicalTerminology(Onlineed.).doi:10.1351/goldbook.T06456.ISBN0967855098.http://goldbook.iupac.org/T06456.html.

When a colour is absorbed from white light, the mix of allthe remaining colours is perceived by the eye as its

complementary colour!eg. Copper(II) sulphate solution is cyan because it absorbs

light in the red region of the spectrum. Cyan is thecomplementary colour of red.

*mixing two complementary colours of light produceswhite light.

5. Crystal Field SplittingCrystal Field Theory describes how electrons fill outenergy levels in the presence of ligands. It describes thestrength of the bonds, but not the actual bonding. Thesplitting of the d-orbitals in transition metals comes aboutdue to the negative ions in the crystal. Since ligands

approach in different directions, different splitting patternsof the d energy level are created, splitting of the energylevels of the d-orbitals into groups - the differences inenergy between these groups are known as crystal fieldsplitting.

A spectrochemical series is a list of ligands ordered onligand strength and a list of metal ions based on oxidationnumber, group and its identity. In crystal field theory,ligands modify the difference in energy between the dorbitals () called theligand-field splitting parameter for ligands or thecrystal-field splitting parameter, which is mainly reflectedin differences in color of similar metal-ligand complexes.References:1. "Ligand." Chemistry Daily. Wikipedia.org, 1 Apr. 2007.Web. 6 Dec. 2012..2.http://www.chemguide.co.uk/inorganic/complexions/colour.htmlLesson 7Homework : Make a www.prezi.com on the following

MnO2 in the decomposition of hydrogenperoxide V2O5 in the Contact process Fe in the Haber process and in heme Ni in the conversion of alkenes to alkanes Co in vitamin B12 Pd and Pt in catalytic converters.

Starter Quiz

Task One Experiment - record what happens and recordyour best guess as to what the reaction/s is/are from yourevidence.

1. to 2mls of Cobalt Chloride solution add conc. HClDROPWISE. After you observe a colour change add distilledwater, DROPWISE to the resultant solution.

2. to 2mls of Copper Sulphate add conc.HCl DROPWISE.After you observe a colour change add distilled water,DROPWISE to the resultant solution.

3. to 2mls of Copper Sulphate add Ammonia DROPWISE.Continue until you see a second change.

4. to 2mls of Cobalt Chlride add Ammonia DROPWISE.Continue until you see a second change.

5. To 2mls of Cr3+ solution add Ammonia DROPWISE.Continue until you see a second change.

6. to 2mls of Chromium Chloride - warm gently.

7. to 2mls of Iron (III) Suplahte add SCN- ions slowly.

Lesson 8

Task One : DEFINition FUN !

1. Ionisation energy - the energy required toremove one mole of electrons from one moleof atoms in their gaseous states - one moleions2. Electronegativity - the ability of an atom toattract a bonding pair of electrons3. Transition metal - forms colouredcomplexes, incomplete d orbital shells,variable oxidation state, act as catalysts (magnetic properties - Fe, Co, Ni )4. Catalyst - offers an alternative lower

energy pathway - the original activationenergy remains the same5. coordination number - the number ofbonds around the central metal ion6. oxidation state - the size and direction ofthe ion.

7. ligands - most likely to be species ormoiety with neutral molecule with a lonepair of electrons, or a formal negativecharge, e.g. chloro, iodo, aqua, ammine,cyano8. dative covalent bond - where bothelectrons originate from the same molecule9. complex ions - have square brackets10. amphoteric - properties of both acid and

base

Task One : Reactions of Chlorides with Water

Task Two : Osama bin laden

Task Three : Formation of complex ions

Coordination / Crystal Field Theory presentations

Lesson 9 - final of 2012 :)

Formative questions pack and christmas reactions 1, 2, and3

Lesson 8 - final of 2012 :)

Formative questions pack and christmas reactions 1, 2, and3

Demo:

Making guncotton : this is used as a propellant and as ablasting explosive.

AHL :

The blue bottle reaction :

Put 200ml water into a flask and dissolve 6g of NaOH.When the NaOH has dissolved add 10g Glucose. WhenGlucose has dissolved add five drops of methylene blue.Allow to stand. When colour changes shake/stand/shake :)

H&S : NaOH solid is VERY corrosive\\Complete coloured complexes