JAMB Chemistry Past Questions & Answers - Page 143

711.

Which of these metals, Mg, Fe, Pb and Cu will dissolve in dilute HCI?

A.

All the metals

B.

Mg ,Fe and Cu

C.

Mg, Fe and Pb

D.

Mg and Fe only

E.

Mg only

Correct answer is D

No explanation has been provided for this answer.

712.

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)

Correct answer is C

No explanation has been provided for this answer.

713.

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

Correct answer is E

No explanation has been provided for this answer.

714.

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

Correct answer is D

No explanation has been provided for this answer.

715.

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

Correct answer is C

No explanation has been provided for this answer.