Jamb Chemistry Past Questions and Answers

Question 326:

• JAMB 1983

Which of the following happens during the electrolysis of molten sodium chloride?

A. Sodium ion loses an electron
B. Chlorine atom gains an electron
C. Chlorine ion gains an electron
D. Sodium ion is oxidized
E. Chloride ion is oxidized

Question 327:

• JAMB 1983

Crude petroleum pollutant usually seen on some Nigerian creeks and waterways can be dispersed or removed by

A. Heating the affected parts in order to boil off the petroleum
B. Mechanically stirring to dissolve the petroleum in water
C. Pouring organic solvents to dissolve the petroleum
D. Spraying the water with stergents
E. Cooling to freeze out the petroleum

Question 328:

• JAMB 1983

An element is electronegative if

A. It has a tendency to exist in the gaseous from
B. Its ions dissolve readily in water
C. It has a tendency to lose electrons
D. It has a tendency to gain electrons
E. It readily froms covalent bonds

Question 329:

• JAMB 1983

Solutions X, Y, and Z have PH values 3.0. 5. 0 and 9. 0 respectively. Which of the following statements is correct?

A. All the solutions are acidic
B. All the solutions are basic
C. Y and Z are more acidic than water
D. Y is more acidic than X
E. Z is the least acidic

Question 330:

• JAMB 1983

In the reactions
(I) H₂ (g) + 1/2O₂(g) → H₂O(l); ∆H = -286 KJ
(II) C(s) + O₂g) → CO₂ (g); ∆H = -406 KJ the equations imply that

A. More heat is absorbed in (l)
B. More heat is absorbed in (ll)
C. Less heat is evolved in (l)
D. Reaction (ll) proceeds faster than (l)
E. Reaction (l) proceeds faster than (ll)