Inorganic Chemistry

Question 1

How can you use Magnesium to extract Titanium, give the equations

Answer 1

TiO2 +2Cl2 + 2C -> TiCl4 + 2CO

Purify in frac distillation with argon atmosphere

TiCl4 + 2Mg -> Ti + 2MgCl2

High temp required
Expensive due to Mg and Argon

Question 2

Describe solubility down group of 2 of their metal Hydroxides

Answer 2

As you go down, solubility increases

Question 3

Describe solubility down group 2 of their metal sulfates

Answer 3

Solubility decreases down the group

Barium sulphate is the most insoluble therefore can be used for X-rays in the mouth

Question 4

How do you test for Ammonium ions NH4+

Answer 4

Add NaOH to NH3Cl
Warm the mixture
Put damp litmus paper at mouth of test tubes
Turns litmus paper blue because of ammonia gas

Question 5

How do you test for sulfates?

Why is HCl added?

Answer 5

Add BaCl and HCl to sulfate ions in test tube
If Sulfate ions present, white ppt forms

HCl is added so the barium doesn’t react with the sulfate ions

Ba2+ + SO4(2-) -> BaSO4

Question 6

How do you test for carbonate ions

Answer 6

Add HCl to Na2CO3

2HCl + Na2CO3 -> 2NaCl + H2O + CO2

Use delivery tube and pass bubble through limewater

Makes limewater go cloudy

Question 7

Testing of Hydroxide ions

Answer 7

Turns red litmus paper blue

Question 8

How do you test for the first 3 halides?

Answer 8

React halide with silver nitrate and dilute nitric acid, to form AgCl, AgBr and AgI

Now add dilute ammonia:
AgCl - white ppt
AgBr - cream ppt
AgI - yellow ppt
Or add conc. ammonia

AgCl - colourless solution
AgBr - colourless solution
AgI - yellow ppt

Question 9

Why does the ammonium salt NaF and NaCl when reacted with conc. Sulfur is acid not produce a H2SO4

Answer 9

Reducing power of halides increase down the group

Therefore Cl- and F- not strong enough reducing agents to reduce
Sulfuric into H2SO4
NaF + H2SO4 -> Na2SO4 + HCl - white steamy fumes
NaCl + H2SO4 -> Na2SO4 + HCl - white steamy fumes

Question 10

What happens if you react NaBr with H2SO4

Answer 10

1. NaBr + H2SO4 -> NaHSO4 + HBr
2. 2HBr + H2SO4 -> Br2 + SO2 + 2H2O

Sulfur goes from 6+ to 4+ as Br- is a stronger reducing agent

Question 11

What Happens if NaI reacts with H2SO4?

Answer 11

1. NaI + H2SO4 -> NaHSO4 + HI
2. 2H+ + 2I- + H2SO4 -> I2 + SO2 + 2H2O : +6 to +4
3. 6H+ + 6I- + H2SO4 -> 3I2 + S + 4H2O : 4+ to 0+
4. 8H+ + 8I- + H2SO4 -> 4I2 + H2SO4 + 4H2O: 0 to 2-

Question 12

What is the colour of a solution with the free Halogen:
1. Chlorne
2.Bromine
3.Iodine

Answer 12

Chlorine - very pale green - often colourless
Bromine - Yellow solution
Iodine - brown solution

Question 13

Write the displacement reaction of Cl2 and Br-
Br2 + 2I-

Answer 13

1. Cl2(aq) + 2Br-> 2Cl- + Br2 (aq)
2. Br2 (aq) + 2I- (aq) -> 2Br- + I2(aq)

Question 14

What happens if [M(H2O)6]2+ reacts with Water

Answer 14

[M(H2O)]