Chemistry Past Questions and Answers

2C₂H_2(g) + 5O_2(g) â†’ 4CO_2(g) + 2H₂O_(g)
In the reaction above, the mass of carbon(IV)oxide produced on burning 78 g of ethyne is
[C =12, O = 16, H = 1]

A 264 g
B 39 g
C 352 g
D 156 g

Question 37:

The ion that can be used as an oxidizing agent is

A Au³⁺
B Fe³⁺
C ClO^-
D Ca²⁺

Question 38:

H_2(g) + Br_2(g) â†’ 2HBr_(g)
The above reaction is carried out at 25^oC. Î”H is -72 kJ mol^-1 and Î”S is - 106 J mol^-1K^-1, the reaction will

A Not proceed spontaneously at the given
B Proceed spontaneously at the given temperature
C Proceed in the reverse direction at the given temperature
D Proceed spontenously at lower temperature

Question 39:

Zinc and carbon rods are used as anode and cathode respectively in a

A Leclanche cell
B Lead accumulator
C Daniel cell
D Voltaic cell

Question 40:

The solution that will conduct the highest amount of electricity is

A 0.5 mol dm^-3 of hydrochloric acid
B 2.0 mol dm^-3 of hydrochloric acid
C 0.5 mol dm^-3 ethanoic acid
D 2.0 mol dm^-3 ethanoic acid