Chemistry Past Questions and Answers

When a solution of silver (l) nitrate is saturated with hydrogen sulphide, a black precipitate forms which is?

A H₂S
B Ag₂S
C PbS
D HNO₃
E S

Question 17:

The production of ammonia by the haber process may be represented by the equilibrium equation N₂(g) + 3H₂(g) â†” 2NH₃ âˆ†H = -22KJ. Therefore the production of ammonia will be favoured by?

A Only high pressure
B Only high temperature
C A combination of high temperature and low pressure
D A combination of low temperature and high pressure
E Low pressure

Question 18:

Which of the following represents ethyl ethanonate?

A CH₃CH₂CO₂CH₃
B (CH₃CO₂)₂O
C CH₃CH₂CO₂CH₂CH₃
D CH₃CO₂CH₂CH₃
E CH₃CH₂COCH₂CH₃

Question 19:

Which of the following equations represents an oxidizing action of sulphur dioxide?

A SO₂ + 2HNO₂ â†’ H₂SO₄ + 2NO₂ + heat
B 2SO₂ + 2H₂O + O₂ → 2H₂SO₄
C SO₂ + 2H₂O + CI₂ â†’ H₂SO₄ + 2HCI
D SO₂ + 2H₂S â†’ 3S + 2H₂O
E K₂Cr₂O₇ + H₂SO₄ + 3SO₂ â†’ K₂SO₄ + Cr₂(SO₄)₃ + H₂O

Question 20:

If the rate of diffusion of oxygen gas is taken as 1, what will be rated of diffusion of methane whose relative molar mass is 16?

A 2.0
B 1.8
C 1.4
D 1.0
E 0.5