Chemistry Past Questions and Answers

The best way to distinguish between Na₂CO₃and NaHCO₂ is by ____________

A Adding an acid.
B Adding an alkali.
C Dissolving in water.
D Exposing to air.
E Heating.

Question 7:

An experiment to test the conductance of 0,1 M solutions of the substances listed below was perform.
I ammonia
II ammonium chloride
III ethanoic acid
IV sodium ethanoate
Which pair of substances show the least conductance?

A I and II
B I and III
C I and IV
D II and III
E II and IV

Question 8:

Faraday s first law of electrolysis can be expressed mathematically as ____________

A M=I/it
B Mαit
C Q=it
D QαI/it
E Qαit

Question 9:

A gas X diffuse through porous partition at the rate of 3 cm₃ per second. Under the same condition hydrogen diffused at the rate of 15 cm₃ per second.

What is the 42. relative molecular mass of X.

A 5
B 12
C 18
D 45
E 50

Question 10:

The green colour solution of an Fe2 salt changes to a brown solution of an Fe3+ salt by ____________

A Conversion.
B Elimination.
C Oxidation.
D Reduction.
E Substitution.