Chemistry Past Questions and Answers

Gunpower is made from charcoal, sulphur and potassium trioxonitrate (V) The salt in the mixture performs the function of

A An oxidant
B A reductant
C A solvent
D A catalyst

Question 27:

Which of the following reactions is (are) feasible?
I Br ₍₁₎ + 2CI _2(aq) 2Br _(aq) + CI _2(g)
ll 21 _(aq) + Br ₂₍₁₎ 2Br _(aq) + 1 _2(s)
lll 2F _(aq) + CI _2(g) 2CI _(aq) + F _2(g) IV 2F _(aq) + Br ₂₍₁₎ 2Br _(aq) + F _2(g)

A L
B Ll
C L and lll
D Lll and lV

Question 28:

Bleaching powder, CaOCI₂, H₂O, deteriorates on exposure to air because

A It loses its water of crystallization
B Atmospheric nitrogen displaces chlorine from it
C Carbon (IV) oxide of the atmosphere displaceschlorine from it
D Bleaching agents should be stored in solution

Question 29:

The products of the thermal decomposition of ammonium trioxonitrate (V) are

A NO ₂ and oxygen
B NH₃ and oxygen
C Nitrogen and water
D N₂O and water

Question 30:

The scale of a chemical balance is made of iron plate and coated with copper electrolytically because

A Iron is less susceptible to corrosion than copper
B Copper is twice as less susceptitible to corrosion as iron
C Copper is less susceptible to corrosion than iron
D Copper and iron are equally susceptible to corrosion