WAEC Chemistry Past Questions & Answers - Page 84

416.

The bond formed between H2O and H+ to form the hydroxonium H3O+ is

A.

Dative

B.

Covalent

C.

Electrovalent

D.

Ionic

Correct answer is A

No explanation has been provided for this answer.

417.

Which of the following elements would produce coloured ion in agueous solution?

A.

Calcuim

B.

Copper

C.

Magnesuim

D.

Sodium

Correct answer is B

No explanation has been provided for this answer.

418.

The shape of the water molecule is_______?

A.

Linear

B.

Pyramidal

C.

Tetrahedral

D.

V-shaped

Correct answer is D

The bond angle in water is compressed approximately to 105°, such that the structure of the water molecule is V-shaped or Angular.

419.

Which of the following arrangements shows increasing order of reactivity of the halogens?

A.

F2 > Cl2 > Br2 >I2

B.

I2 < Br2 < Cl2

C.

F2 < Cl2 < Br2

D.

I2 > Br2 > Cl2 > F2

Correct answer is B

The reactivity of halogens decreases as you move down Group 7.

Halogens become less reactive as you move down the group as the atomic radius of the element increases which means that the distance between the outer shell of electrons and the nucleus increases.

420.

An unsaturated solution differs from a saturated solution at a given temperature because it

A.

Cannot dissolve more solute

B.

Can hold more solute than it can actually dissolve

C.

Can still dissolve more solute at given temperature

D.

Form crystal more easily on cooling

Correct answer is C

An unsaturated solution contains a lesser amount of solute than that in a saturated solution. It can go on to dissolve more quantities of solute at the same temperature until it becomes a saturated solution.