Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

1,107.

The high boiling point of hydrogen fluoride can be explained in terms of

A.

covalent bonds.

B.

dative bonds.

C.

dipole-dipole bonds.

D.

electrovalent (ionic) bonds

E.

hydrogen bonds.

Correct answer is E

No explanation has been provided for this answer.

1,108.

The oxidation number of X in \(XO_{4}^{3-}\) is

A.

1

B.

-2

C.

3

D.

4

E.

5

Correct answer is E

The oxidation number of O  is 2-

Therefore, let the oxidation number of X be a

a + (-2 x 4) = -3

a - 8 = -3

a = -3+8

a = 5

1,109.

How much sodium hydroxide is required to make 250 cm3 of 0.1 molar solution? Na=23; 0=16; H=1]

A.

10.0 g

B.

4.0g

C.

2.0 g

D.

1.0g

E.

0.1 g

Correct answer is D

no of moles of Na = molar concentration X   volume

                             = 0.1 x \(\frac{250}{1000}\) = 0.025

no of moles =  \(\frac{m}{M}\) 

mass = no of mles x molar mass = 0.025 x 40 = 1.0g ( molar mass of NaOH = 40g/mol)

1,110.

What is the ratio of the rate of diffusion of carbon(IV) oxide to that of propane, under the same conditions? [H = 1; C= 12; 0= 161

A.

1:01

B.

1:01

C.

2:01

D.

2:03

E.

3:01

Correct answer is A

No explanation has been provided for this answer.