Year : 
2005
Title : 
Chemistry
Exam : 
JAMB Exam

Paper 1 | Objectives

31 - 40 of 49 Questions

# Question Ans
31.

A heterogenous mixture can be defined as any mixture

A. of a solute nd a solvent

B. whose cmposition is uniform

C. whose composition is not uniform

D. formed by solids and liquids

C
32.

The pressure of 100cm3 of oxygen at 35oC is 750mmHg. What will be the volume of gas if the pressure is reduced to 100mmHg without changing the temperature?

A. 650 cm3

B. 850 cm3

C. 580 cm3

D. 750 cm3

D
33.

I. Treatment of cancer
II. Detection of leakages in water mains
III. Detection of the ages of ancient tools
IV. Preparation of drugs
Which combination of the above refers to the uses of radioactive isotopes?

A. I and III

B. I and II

C. I, II and III

D. I, II, III and IV

D
34.

What is the valence shell electron configuration of the element with atomic number 17?

A. 1s2 2s2 2p6 3s2 3p4

B. 1s2 2s2 2p6 3s2 3p5

C. 2s2 2p6

D. 3s2 3p5

Detailed Solution

It's important to take note of "valence shell" used in the presentation of the question.
Hence; Option D carries the answer as specified in the question.
35.

The density of a certain gas is 1.98gdm-3 at s.t.p. What is the molecular mas of the gas?

A. 44.0 g

B. 54.0 g

C. 26.0 g

D. 31.0 g

Detailed Solution

Density = mass/volume
∴ 1.98 = molecular mass/22.4
molecular mass = 1.98 * 22.4 = 44.35 ≅ 44.05
36.

When pure aluminium metal is heated to red hot in the presence of nitrogen gas, the compound formed is

A. Al2N

B. Al2N2

C. AlN

D. Al2N3

C
37.

A dense white fume is formed when ammonia gas reacts with

A. O2(g)

B. H2(g)

C. Cl2(g)

D. HCl(g)

D
38.

N2(g) + 3H2(g) ↔ 2NH3(g) ΔH = -90 kJ
In the equation above, the yield of ammonia can be decreased by

A. increasing the pressure

B. removing the ammonia as it is formed

C. increase the temperature

D. adding a catalyst

C
39.

The gas that can be dried using concentrated tetraoxosulphate (VI) acid is

A. hydrogen bromide

B. Sulphur (IV) oxide

C. hydrogen sulphide

D. ammonia

B
40.

NH4Cl(s) ↔ NH3(g) + HCL(g)
The reaction above can only attain equilibrium if

A. a gaseous reactant is added

B. one of the products is removed

C. it is in a closed system

D. it is an open system

C
31.

A heterogenous mixture can be defined as any mixture

A. of a solute nd a solvent

B. whose cmposition is uniform

C. whose composition is not uniform

D. formed by solids and liquids

C
32.

The pressure of 100cm3 of oxygen at 35oC is 750mmHg. What will be the volume of gas if the pressure is reduced to 100mmHg without changing the temperature?

A. 650 cm3

B. 850 cm3

C. 580 cm3

D. 750 cm3

D
33.

I. Treatment of cancer
II. Detection of leakages in water mains
III. Detection of the ages of ancient tools
IV. Preparation of drugs
Which combination of the above refers to the uses of radioactive isotopes?

A. I and III

B. I and II

C. I, II and III

D. I, II, III and IV

D
34.

What is the valence shell electron configuration of the element with atomic number 17?

A. 1s2 2s2 2p6 3s2 3p4

B. 1s2 2s2 2p6 3s2 3p5

C. 2s2 2p6

D. 3s2 3p5

Detailed Solution

It's important to take note of "valence shell" used in the presentation of the question.
Hence; Option D carries the answer as specified in the question.
35.

The density of a certain gas is 1.98gdm-3 at s.t.p. What is the molecular mas of the gas?

A. 44.0 g

B. 54.0 g

C. 26.0 g

D. 31.0 g

Detailed Solution

Density = mass/volume
∴ 1.98 = molecular mass/22.4
molecular mass = 1.98 * 22.4 = 44.35 ≅ 44.05
36.

When pure aluminium metal is heated to red hot in the presence of nitrogen gas, the compound formed is

A. Al2N

B. Al2N2

C. AlN

D. Al2N3

C
37.

A dense white fume is formed when ammonia gas reacts with

A. O2(g)

B. H2(g)

C. Cl2(g)

D. HCl(g)

D
38.

N2(g) + 3H2(g) ↔ 2NH3(g) ΔH = -90 kJ
In the equation above, the yield of ammonia can be decreased by

A. increasing the pressure

B. removing the ammonia as it is formed

C. increase the temperature

D. adding a catalyst

C
39.

The gas that can be dried using concentrated tetraoxosulphate (VI) acid is

A. hydrogen bromide

B. Sulphur (IV) oxide

C. hydrogen sulphide

D. ammonia

B
40.

NH4Cl(s) ↔ NH3(g) + HCL(g)
The reaction above can only attain equilibrium if

A. a gaseous reactant is added

B. one of the products is removed

C. it is in a closed system

D. it is an open system

C