Neco Chemistry Past Questions and Answers

Question 6:

• NECO 2001

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:

• NECO 2001

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:

• NECO 2001

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:

• NECO 2001

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:

• NECO 2001

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.