AQA AS Chemistry INORGANIC

Write the simplest ionic equation for when chlorine water reacts with aq potassium iodide soluion

Cl2 + 2I- —> 2Cl- + I2

Define periodicity

A REPEATING pattern/trend for all periods of physical/chemical properties

for group 2, what happens to reactivity and why?

As you go down a group, reactivity INCREASES because atomic radius increases, weaker EFA and electron easier to remove

Colour of fluorine

pale yellow gas

colour of chlorine

pale green gas

Colour of bromine and bromide

Br2 → Browny orange liquid

Br- → ions Yellow solution

Colour of iodine solid

Black

which is the best oxidising agent of group 7? Why?

Fluorine

Most electronegative element (smallest size, least shells and shielding) therefore easily gains electrons

which is the strongest reducing agent of the halide ions? WHY?

iodide ions

Highest ionic radius, most shells and shielding, so least EFA therefore more easily loses electrons

Define disproportionation

The simultaneous oxidation and reduction of the same species

how to test for ammonium compounds (include eq)

Test for sulfates (include eq)

What is an exception for group 2 melting points

Mg, is MUCH lower than expected because of a structural difference compared to other group 2 metals

Write ionic equation for formation of BaSO4

Ba (2+) (aq) + SO4 (2-) (aq) --> BaSO4 (s)

Write the ionic equation for a neutralisation reaction.

H+ (aq) + OH- (aq) --> H2O (l)

Define reducing agent

•Readily donates electrons

•Substance that is oxidised

Define oxidizing agent

something that removes electrons from something else and itself is reduced

Why does group 4 have the highest melting point?

-giant covalent (strong) macromolecular lattice structure that needs lots of energy to break

Describe melting point across a period

group 1 - 3: increases (because metallic bonding strengthens as more delocalised electrons and smaller ionic radius)

group 4: peaks (because strong macromolecular lattice covalent structure)

group 5 - 8: decreases (because weak(er) simple molecular structure)

Describe electrical conductivity across a period

increases up to group3 and then decreases

what type of metal are group 4 elements

semi metal

name of group 2 elements

alkaline earth metals

write general equation for group 2 metals reacting with oxygen

2M (s) + O2 (g) --> 2MO (s)

write general equation for group 2 metals reacting with chlorine

M (s) + Cl2 (g) —> MCl2 (s)

write general (balanced) equation for group 2 metals with water (liquid)

M (s) + 2H2O (l) —> M(OH)2 (aq/s) + H2 (g)

write general (balanced) equation for reaction between magnesium with steam

M (s) + H2O (g) —> MO + H2 (g)

In reactions, what is the role of group 2 metals?

reducing agent i.e. gets oxidised itself (donates electrons)

How is Ti extracted? (include equations)

Why is Titanium a useful metal?

Abundant, low density, corrosion resistant, strong, light alloys

What type of agent are halide ions?

reducing agent

down group 7, what happens to boiling point?

boiling point increases because more electrons/larger atom = more VDW that require more energy to break

What happens in a displacement reaction? (7)

most reactive halogen removes electron from less reactive halide ion

Give ionic equation for displacement reaction (halogens) - bromide ions reacting with chlorine

Cl2 (aq) + 2Br- (aq) —> Br2 (aq) + 2Cl- (aq)

Write the ionic equation for a neutralisation reaction.

H+(aq) + OH-(aq) --> H2O(l)

what are disadvantages of using chlorine to purify swimming pools

- chlorine gas is toxic

- chlorine liquid causes chemical burns

- chloroalkanes could be formed, which could cause cancer

- needs frequent chlorine input

- if reacting chlorine and water, HCl could be produced which is corrosive to metal fittings

Give an example of a reagent which could be used to show that the reducing ability of bromide ions is different from that of chloride ions

concentrated sulfuric acid

name the 3 reduction products (when iodide ions reduce sulfuric acid) and give the oxidation state of sulfur in each of these products

- sulfur dioxide (+4)

- sulfur (0)

- hydrogen sulfide (-2)

observation when silver nitrate solution is added to aq potassium chloride solution. Write an ionic equation for this.

Ag+ (aq) + Cl- (aq) —> AgCl (s)

white precipitate of silver chloride

observation when silver nitrate solution is added to aq potassium bromide solution. Write an ionic equation for this.

Ag+ (aq) + Br- (aq) —> AgBr (s)

Cream precipitate of silver bromide

Write the simplest ionic equation or when concentrated sulfuric acid reacts with solid potassium chloride

H2SO4 + 2Cl- —> 2HCl + SO4(2-)

why is IE an endothermic reaction

heat/E needed to overcome EFA between e- and positive nucleus

deduce the redox half equation for the reduction of the nitrate ion in acidified solution to form nitrogen monoxide and water

4H+ + NO3- + 3e- —> 2H2O + NO

explain why a reaction involving aluminium is expensive

aluminium extracted by electrolysis/uses electricity —> requires lots of energy (AKA money)

Barium chloride solution added magnesium sulfate solution. mixture was filtered. give the formulae of the two main ions in the filtrate

Mg2+ and Cl-

Deduce the half equation for the formation of NO from NO3- ions in the presence if H+ ions.

4H+ + NO3- + 3e- --> NO + 2H20

Write the simplest ionic equation for the reaction that occurs when acidified barium chloride solution is added to a solution containing sulphate ions

Ba^2+ + SO4^2- --> BaSO4

Explain why the halogens are all oxidising agents and state and explain the trend in oxidising ability of halogens

- they all have 7 e- in their outer shell therefore will all gain an electron to form halides (i.e. get reduced themselves)

- oxidising ability increases up the group because atoms are smaller, less shells + shielding and the electrons are more attracted to positive nucleus therefore it's easier to gain an electron

Explain why the halides are all reducing agents and state and explain the trend in reducing ability of the halides

gets oxidised itself because loses electron itself to become halogens. reducing ability increases down the grouo because larger ionic radius with more shells + shielding means that there is lower EFA between nucleus and e- therefore electrons are lost more easily

Write a half equation for when H2SO4 turns into SO2

2e- + 2H+ + H2SO4 —> SO2 + 2H2O

explain why chlorine is used to sterilise water even though it's toxic

- small amounts/ low doses

- health benefits outweigh the risks

- after reaction, little remains

Develop a procedure to get a pure sample of silver bromide from a mixture of sodium chloride and sodium bromide

Write an ionic equation to show, with state symbols, to show the reaction of calcium with an excess of water

Ca (s) + 2H2O (l) --> Ca2+ (aq) + 2OH- (aq) + H2 (g)

State the role of water in a reaction with calcium

Oxidising agent

If there is a huge jump between 6th and 7th IE, which group is this element in?

group 6

A solution of sodium chlorate (I) was added to a colourless solution of potassium iodide. Suggest and explain what is observed

grey solid of I2 forms because I- is oxidised

TRUE OR FALSE: chlorine reacts with water to form an alkaline solution

faLSE

Which is the best technique to remove the silver chloride that forms when aqueous solutions of silver nitrate and sodium chloride react?

Filtration

Define oxidation

•loss of electrons

•gain of O₂

•Loss of H₂

•Increase in oxidation number

Define reduction

•gain of electrons

•loss of O₂

•gain of H₂

•decrease in oxidation number

Define oxidation state

shows number of e- donated/accepted

oxidation number of simple monatomic ion

same as charge

Exceptions to the oxidation state of oxygen?

- Molecular oxygen where it is 0

- peroxides: -1

- OF2: 2+

- O2F2: 1+

Why do transition metals have highest melting points out of all metals?

HIGHEST electron charge density = strong metallic lattice

Why is group 1 more reactive than group 2?

"energetically more feasible" because it's easier to lose 1 e- than 2 e-

Colours of group 2 metals in flame tests

above Ca: no colour

Ca: brick red

Sr: red

Ba: green

Trend in solubility of group 2 (down group)

- sulfates decrease

- hydroxides increase

Explain trend in reactivity of group 2 metals down a group

reactivity increases

because atomic radius increases, lower EFA, easier to remove e-

Down group 2 what happens to mp, why

decreases

because delocalised e- further from nucleus, lower EFA, metallic bond strength decreases

EXCEPTION: Mg because VERY LOW because structural difference to other group2 metals

Give 4 uses of group 2 metals

- BaSO4: barium meal (for x-rays because coat tissue in stomach). insoluble therefore safe to use because won't get absorbed into blood

- Mg(OH)2: milk of magnesia for indigestion

- Ca(OH)2: slaked lime, acidic soil treatment

- BaCl2: sulfate test

Describe hydroxide test

turns red litmus paper blue because alkaline

Describe carbonates test. include eq

1. add acid

2. carbon dioxide is made

3. bubble thru limewater

4. limewater should turn cloudy

Equation for 1st/2nd step: CO3^2- + 2H+ --> CO2 + H2O

if something is very soluble, what is its thermostability?

v soluble = least thermally stable (opposites basically)

What does solubility depend on

polarising ability of cation and anion.

big big and small small don't work

big and small DO work

Write equation for when chlorine reacts with water

Write equation for when chlorine reacts with water in SUNLIGHT

Write equation for an alternative to direct chlorination using sodium chlorate (I)

Describe test for halide ions IN detail, giving equations and results for each

Write equation for reaction of NaCl (s) with concentrated sulphuric acid. What is the role of the sulphuric acid? Observations?

Write equations for when NaBr reacts with concentrated sulphuric acid. Observations and role of sulphuric acid for each step

Write equations for when NaI reacts with concentrated sulphuric acid, IN DETAIL with observations and role of sulphuric acid in each step.

Write an equation for when chlorine gas reacts with cold dilute sodium hydroxide. Give 2 roles of product formed. Give ox state of chlorine for both of the chlorine containing products formed

Use Le chateliers principle to explain why equilibrium formed (when chlorine reacts with water) moves to the right when sodium hydroxide solution is added to it.

Why can chlorine can be used to sterilise pools even though it is toxic

Explain the trend in electronegativity of elements down group 7

which is the most reactive halogen? (except F2)

chlorine