WAEC Past Questions and Answers - Page 1755

8,771.

Alkanols have unexpectedly high boiling points relative to their molar masses because of intermolecular

A.

hydrogen bonding

B.

metallic bonding

C.

covalent bonding

D.

ionic bonding

E.

van der Waals' forces

Correct answer is A

No explanation has been provided for this answer.

8,772.

What is the molar of hydrogen sulphide gas in the reaction H2SO4(aq) + 3H2S(g) → 4S(s) + 4H2O (l)n represented by the following equation?

A.

Reducing agent

B.

A bleaching agent

C.

A dehydrating agent

D.

A sulphonating agent

E.

An oxidizing agent

Correct answer is A

No explanation has been provided for this answer.

8,773.

Which of the following reactions is accompanied by the first ionization energy of an element X?

A.

X +(aq) → X 2+ (aq) + e-

B.

X - (g) → X(g) + e-

C.

X+ (g) → X2+ +e-

D.

X (g) → X+ (g) +e-

E.

X(s) → X + (g) + e-

Correct answer is D

 ionization energy (IE) is the minimum energy required to remove an isolated gaseous atom's most loosely bound electron. The first ionization energy is quantitatively expressed as

\(X_{(g)} + energy ⟶ X^+_{(g)} + e^−\)

where X is any atom or molecule, \(X^+\) is the resultant ion when an electron( \(e^−\)) was removed from the original atom.

8,774.

The following compounds will decompose on heating except

A.

NaHCO3

B.

K2CO3

C.

MgCO3

D.

Ca(HCO3)2

E.

ZnCO3

Correct answer is B

No explanation has been provided for this answer.

8,775.

n a chemical reaction, the reacting species possess energy of motion known as

A.

potential energy

B.

free energy

C.

bond energy

D.

kinetic energy

E.

hydration energy

Correct answer is D

No explanation has been provided for this answer.