WAEC Past Questions and Answers - Page 1385

6,921.

Which of the following statements about solids is correct?

A.

Solid particles are less orderly than those of a liquid

B.

Solid have lower densities than liquids

C.

Solid particles have greater kinetic energies than those of liquids

D.

Solid particles cannot be easily compressed

Correct answer is D

No explanation has been provided for this answer.

6,922.

How many moles of oxygen would contain 1.204 x 1024 molecules?
[Avogadro's constant (NA) = 6.02 x 1023]

A.

1

B.

2

C.

3

D.

4

Correct answer is B

6.02 x 1023 molecules is 1mole
1.204 x 1024 molecules will be......

\(\frac{1.204 \times 10^24 \times 1}{6.02 \times 10^23}\)

\(\frac{1.204 \times 10}{6.02}\) = \(\frac{12.04}{6.02}\) = 2moles

6,923.

An element X froms the following oxides X2O, XO and XO2. This phenomenon illustrates the law of________?

A.

Conservation of mass

B.

Definite proportion

C.

Mass action

D.

Multiple proportion

Correct answer is D

No explanation has been provided for this answer.

6,924.

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.

6,925.

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.