Year : 
2019
Title : 
Chemistry
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

31 - 40 of 50 Questions

# Question Ans
31.

If a catalyst is added to a system, the temperature and the pressure remain constant, there would be no effect on the?

A. activation energy of the reaction

B. rate of the reaction

C. rate of the reverse reaction

D. heat of reaction

D
32.

Consider the following reaction equation: 2NH\(_3 \) .+ 3Cl\(_2\) → N2 + 6HCl. NH\(_3\) is acting as?

A. a reducing agent

B. a dehydrating agent

C. a drying agent

D. an oxidizing agent

Detailed Solution

- As a reducing agent, Ammonia reacts with chlorine to create nitrogen gas and hydrogen chloride vapour in the first step.
33.

The oxidation of chromium in Cr\(_2\)O\(_7)\(-2\) ?

A. +4

B. +5

C. +6

D. +7

Detailed Solution

2 atoms of Cr,
7 X -2 atoms of O
2Cr - 14 = -2
2Cr = -2 + 14
2Cr = 12
Cr = 6
34.

The process by which alkanoic acid reacts reversibly with alkanols is known as?

A. saponification

B. esterification

C. carboxylation

D. halogenation

B
35.

If the oxidation potential of Mg and Al are +2.37 volts and + 1.66 volts respectively, then the Mg would?

A. not replace Al

B. be replaced by Al

C. remain in the solution

D. replace Al

Detailed Solution

Cation which is lower in the series (less electropositive) will show a greater tendency to be discharged.
36.

Consider the reaction represented by the following equation: 2SO\(_2\) + O\(_2\) ⇌ 2SO\(_3\) A decrease in the pressure of the reaction would

A. decrease in the concentration of SO\(_2\)

B. have no effect on the reaction

C. shift the equilibrium position to the left

D. shift the equilibrium position to the right

Detailed Solution

decrease in pressure favors the side with higher volume thus the equilibrium position will shift to the left
37.

In a mixture of gases which do not react chemically together, the pressure of the individual gas is?

A. atmospheric pressure

B. vapor pressure

C. total pressure

D. partial pressure

Detailed Solution

The pressure exerted by an individual gas in a mixture is known as its partial pressure
38.

Biotechnology is applied in the?

A. treatment of sewage

B. treatment of water

C. purification of chemicals

D. purification of metals

Detailed Solution

There are several wastewater treatment methods based on biotechnology that are used worldwide. It includes Activated Sludge, Oxidation Ponds, Tricking Filters, Bio-filters and Anaerobic treatment. All the methods are part of the biological wastewater treatment and use microbes to treat organic waste in sewage.
39.

Which of the following organic compounds has the lowest boiling point?

A. C\(_6\)H\(_14\)

B. C\(_5\)H\(_12\)

C. C\(_4\)H\(_10\)

D. ( CH\(_3\) )\(_3\)

Detailed Solution

- The boiling points of alkanes increase with increasing number of carbons. This is because the intermolecular attractive forces, although individually weak, become cumulatively more significant as the number of atoms and electrons in the molecule increases.
- However; branched alkanes normally exhibit lower boiling points than unbranched alkanes of the same carbon content. This occurs because of the greater van der Waals forces that exist between molecules of the unbranched alkanes
40.

Consider the following reaction represented by the following equation: C\(_2\)H\(_2\) \(^{H\(_2\)}_{→}\) X \(^{H\(_2\)}_{→}\) Y. X and Y respectively are?

A. ethane and ethene

B. ethene and ethane

C. ethyne and ethene

D. ethane and ethyne

B
31.

If a catalyst is added to a system, the temperature and the pressure remain constant, there would be no effect on the?

A. activation energy of the reaction

B. rate of the reaction

C. rate of the reverse reaction

D. heat of reaction

D
32.

Consider the following reaction equation: 2NH\(_3 \) .+ 3Cl\(_2\) → N2 + 6HCl. NH\(_3\) is acting as?

A. a reducing agent

B. a dehydrating agent

C. a drying agent

D. an oxidizing agent

Detailed Solution

- As a reducing agent, Ammonia reacts with chlorine to create nitrogen gas and hydrogen chloride vapour in the first step.
33.

The oxidation of chromium in Cr\(_2\)O\(_7)\(-2\) ?

A. +4

B. +5

C. +6

D. +7

Detailed Solution

2 atoms of Cr,
7 X -2 atoms of O
2Cr - 14 = -2
2Cr = -2 + 14
2Cr = 12
Cr = 6
34.

The process by which alkanoic acid reacts reversibly with alkanols is known as?

A. saponification

B. esterification

C. carboxylation

D. halogenation

B
35.

If the oxidation potential of Mg and Al are +2.37 volts and + 1.66 volts respectively, then the Mg would?

A. not replace Al

B. be replaced by Al

C. remain in the solution

D. replace Al

Detailed Solution

Cation which is lower in the series (less electropositive) will show a greater tendency to be discharged.
36.

Consider the reaction represented by the following equation: 2SO\(_2\) + O\(_2\) ⇌ 2SO\(_3\) A decrease in the pressure of the reaction would

A. decrease in the concentration of SO\(_2\)

B. have no effect on the reaction

C. shift the equilibrium position to the left

D. shift the equilibrium position to the right

Detailed Solution

decrease in pressure favors the side with higher volume thus the equilibrium position will shift to the left
37.

In a mixture of gases which do not react chemically together, the pressure of the individual gas is?

A. atmospheric pressure

B. vapor pressure

C. total pressure

D. partial pressure

Detailed Solution

The pressure exerted by an individual gas in a mixture is known as its partial pressure
38.

Biotechnology is applied in the?

A. treatment of sewage

B. treatment of water

C. purification of chemicals

D. purification of metals

Detailed Solution

There are several wastewater treatment methods based on biotechnology that are used worldwide. It includes Activated Sludge, Oxidation Ponds, Tricking Filters, Bio-filters and Anaerobic treatment. All the methods are part of the biological wastewater treatment and use microbes to treat organic waste in sewage.
39.

Which of the following organic compounds has the lowest boiling point?

A. C\(_6\)H\(_14\)

B. C\(_5\)H\(_12\)

C. C\(_4\)H\(_10\)

D. ( CH\(_3\) )\(_3\)

Detailed Solution

- The boiling points of alkanes increase with increasing number of carbons. This is because the intermolecular attractive forces, although individually weak, become cumulatively more significant as the number of atoms and electrons in the molecule increases.
- However; branched alkanes normally exhibit lower boiling points than unbranched alkanes of the same carbon content. This occurs because of the greater van der Waals forces that exist between molecules of the unbranched alkanes
40.

Consider the following reaction represented by the following equation: C\(_2\)H\(_2\) \(^{H\(_2\)}_{→}\) X \(^{H\(_2\)}_{→}\) Y. X and Y respectively are?

A. ethane and ethene

B. ethene and ethane

C. ethyne and ethene

D. ethane and ethyne

B