Neco Chemistry 2008 Past Questions and Answers

Question 16:

• NECO 2008

During the electrolysis of sodium Chloride solution, hydrogen is discharged at the carbon cathode because ____________

A. Hydrogen ions are in greater concentration than sodium ions.
B. Hydrogen is higher than sodium in the electrochemical series.
C. Hydrogen is lower than sodium in the electrochemical series.
D. Of the nature of the electrodes.
E. The concentration of sodium ions is greater than that of the hydrogen ion in the electrolyte.

Question 17:

• NECO 2008

Chromatography is used to separate components of mixtures which differ in their rates of ____________

A. Diffusion
B. Migration
C. Reaction
D. Sedimentation
E. Sublimation.

Question 18:

• NECO 2008

The electrode potential in volts of 2H+(aq) / H2(q) system is ____________

A. -2.87
B. -2.71
C. 0.8
D. 1.68
E. \( 0 \)

Question 19:

• NECO 2008

A substance is said to be hygroscopic when it ____________

A. Absorbs atmospheric moisture and then goes into solution
B. Absorbs atmospheric moisture but does not go into solution
C. Changes colour
D. Is not affected by atmospheric moisture
E. Losses its water of crystallization

Question 20:

• NECO 2008

A measure of the degree of disorderliness in a chemical system is known as the ____________

A. Activation energy
B. Enthalpy
C. Entropy
D. Equilibrium
E. Free energy.