Inorganic Chemistry AS

Question 1

Explain the extraction of Titanium

Answer 1

1. Conversion to TiCl4 by heating TiO2 (ore) with carbon in a stream of chlorine gas
2. Purification of TiCl4 by fractional distillation
3. Reduction by reacting TiCl4 with Magnesium at almost 1000°C where:

TiCl4 (g) + 2Mg (l) —-> Ti (s) + 2MgCl2 (s)

Question 2

Why can’t Titanium be extracted from it’s ore by reaction with carbon?

Answer 2

Titanium reacts with Carbon to form Titanium Carbide (TiC) which is brittle

Question 3

Does solubility of hydroxides down group 2 increase or decrease?

Answer 3

Increase

Question 4

Does solubility of sulphates down group 2 increase or decrease

Answer 4

Decrease

Question 5

Why is the melting point of calcium (below Magnesium in group 2) higher than Magnesium

Answer 5

There is a different crystal structure concerning the arrangement of metal ions in calcium making it require more energy to break.

Question 6

Trend of melting points across periods

Answer 6

No trend, melting point depends on structure and bonding of elements across a period.

Question 7

What are flue gases?

Answer 7

Gases emitted from industrial exhausts or chimneys

Question 8

How is acidic sulfur dioxide (SO2) removed from flue gases?

Answer 8

Wet scrubbing which involves powdered CaO or CaCO3 mixed with water to form a slurry that is sprayed onto flue gas. The reaction of sulfur dioxide with the ALKALINE slurry produces calcium sulfite in the following reactions:

CaO (s) + 2H2O (l) + SO2 (g) –> CaSO3 (s) + 2H2O (l)

CaCO3 (s) + 2H2O (l) + SO2 (g) –> CaSO3 (s) + 2H2O (l) + CO2 (g)

Question 9

What is a halide?

Answer 9

A compound with a -1 halogen ion

Question 10

how do halogens and halide solutions react

Answer 10

The halogen displaces the halides from their solutions if the halide is less reactive (below in the periodic table).

Question 11

Reaction of Chlorine with water to kill bacteria

Answer 11

Cl2 (g) + H2O (l) <=> 2H+ (aq) + Cl- (aq) + ClO- (aq)
which results in:
Cl2 (g) + H2O (l) <=> HClO(aq) + HCl(aq)

Question 12

Reaction for making Bleach (Sodium Chlorate I solution)

Answer 12

2NaOH (aq) + Cl2(g) –> NaClO (aq) + NaCl (aq) + H2O (l)

Question 13

2 Risks of chlorine for water treatment

Answer 13

Cl gas irritates the respiratory system and liquid chlorine causes severe chemical burns.

Question 14

How does reducing power of halides change down the group

Answer 14

Increases

Question 15

What product does reaction of halides with sulfuric acid give

Answer 15

A hydrogen halide

Question 16

NaF, NaCl and NaBr reaction with H2SO4 products in order

Answer 16

1. NaHSO4 (s) + HF (g)
2. NaHSO4 (s) + HCl (g)
3. NaHSO4 (s) + HBr (g)

HBr reacts again:

2HBr (aq) + H2SO4 (l) –> Br2 (g) + SO2 (g) + 2H2O (l)

Question 17

How does the rate of formation of an AgX precipitate change as you go down group 7.

Answer 17

Increases (slowest at top, fastest at bottom)

Question 18

Solubilities of Cl, Br and I in nitric acid

Answer 18

1. Dissolves in dilute
2. Dissolves in conc.
3. Insoluble in conc.

(CLBri)

Question 19

Why is nitric acid after the silver nitrate test

Answer 19

To distinguish between silver halide precipitates since they have different solubilities in nitric acid.

Question 20

Reaction of HCl and carbonates and identify how this can be used in ion tests

Answer 20

CaCO3(s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)
(general equation)
CO3 2- (s) + 2H+ (aq) —> CO2 (g) + H2O (l)

CO2 gas produced

Question 21

reaction to convert NH4 to NH3

Answer 21

NH4+ (aq) + OH-(aq) –> NH3(g) + H2O (l)