Year : 
2009
Title : 
Chemistry
Exam : 
JAMB Exam

Paper 1 | Objectives

41 - 50 of 50 Questions

# Question Ans
41.

Which of the following molecules has two other positional isomers?

A. CH3CH2Br

B. CH3CHBrCH3

C. CBr2F2

D. CH2CHBrCH2Br

Detailed Solution

Positional isomers of C\(_3\)H\(_7\)Br : 1- bromo propane and 2- bromo propane
There is an explanation video available below.
42.

Which of the following class of compounds can exist as dipolar ions in solution?

A. Alkanoic acid

B. Fatty acids

C. Dialkanoic acids

D. Amino acids

Detailed Solution

There is an explanation video available below.
43.

Lucas reagent is used to test for?

A. alkanes

B. alkanoic acids

C. alkanols

D. amines

Detailed Solution

Lucas' reagent is a solution of anhydrous zinc chloride in concentrated hydrochloric acid. This solution is used to classify alcohols.
There is an explanation video available below.
44.

A compound commonly used for sterilization and preservation of specimens and food is

A. ethanol

B. benzene

C. ether

D. ammonia

Detailed Solution

There is an explanation video available below.
45.

An organic compound reacted with bromine water to give a colourless solution. The compound is probably an?

A. alkene

B. alkanal

C. alkyl

D. alkanone

Detailed Solution

Alkenes react in the cold with pure liquid bromine, or with a solution of bromine in an organic solvent like tetrachloromethane. The double bond breaks, and a bromine atom becomes attached to each carbon. The bromine loses its original red-brown colour to give a colourless liquid.
Alkynes also react with bromine, decolorising it though not as immediate as alkenes.
There is an explanation video available below.
46.

Which of the following hydrocarbons is mainly used as fuel?

A. Methylene

B. Ethylene

C. Methane

D. Ethyne

Detailed Solution

There is an explanation video available below.
47.

The molecular formula of a common organic laboratory anaesthetic is

A. CHCl3

B. CHI3

C. CCl4

D. CHF3

Detailed Solution

There is an explanation video available below.
48.

The simplest branched-chain hydrocarbon is

A. ethane

B. ethene

C. propane

D. butane

Detailed Solution

The smallest branched alkane is isobutane. Notice that isobutane has the same molecular formula, C4H10, as n-butane but has a different structural formula.
There is an explanation video available below.
49.

Organic molecules that have the suffix-ene are unsaturated hydrocarbons that have?

A. a single bond

B. a double bond

C. a triple bond

D. an ionic bond

Detailed Solution

In chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.
There is an explanation video available below.
50.

If the relative atomic mass of an element is not a whole number, it can be deduced that the element is?

A. Naturally radioactive

B. abundant in nature

C. a transition metal

D. an isotopic mixture

Detailed Solution

There is an explanation video available below.
41.

Which of the following molecules has two other positional isomers?

A. CH3CH2Br

B. CH3CHBrCH3

C. CBr2F2

D. CH2CHBrCH2Br

Detailed Solution

Positional isomers of C\(_3\)H\(_7\)Br : 1- bromo propane and 2- bromo propane
There is an explanation video available below.
42.

Which of the following class of compounds can exist as dipolar ions in solution?

A. Alkanoic acid

B. Fatty acids

C. Dialkanoic acids

D. Amino acids

Detailed Solution

There is an explanation video available below.
43.

Lucas reagent is used to test for?

A. alkanes

B. alkanoic acids

C. alkanols

D. amines

Detailed Solution

Lucas' reagent is a solution of anhydrous zinc chloride in concentrated hydrochloric acid. This solution is used to classify alcohols.
There is an explanation video available below.
44.

A compound commonly used for sterilization and preservation of specimens and food is

A. ethanol

B. benzene

C. ether

D. ammonia

Detailed Solution

There is an explanation video available below.
45.

An organic compound reacted with bromine water to give a colourless solution. The compound is probably an?

A. alkene

B. alkanal

C. alkyl

D. alkanone

Detailed Solution

Alkenes react in the cold with pure liquid bromine, or with a solution of bromine in an organic solvent like tetrachloromethane. The double bond breaks, and a bromine atom becomes attached to each carbon. The bromine loses its original red-brown colour to give a colourless liquid.
Alkynes also react with bromine, decolorising it though not as immediate as alkenes.
There is an explanation video available below.
46.

Which of the following hydrocarbons is mainly used as fuel?

A. Methylene

B. Ethylene

C. Methane

D. Ethyne

Detailed Solution

There is an explanation video available below.
47.

The molecular formula of a common organic laboratory anaesthetic is

A. CHCl3

B. CHI3

C. CCl4

D. CHF3

Detailed Solution

There is an explanation video available below.
48.

The simplest branched-chain hydrocarbon is

A. ethane

B. ethene

C. propane

D. butane

Detailed Solution

The smallest branched alkane is isobutane. Notice that isobutane has the same molecular formula, C4H10, as n-butane but has a different structural formula.
There is an explanation video available below.
49.

Organic molecules that have the suffix-ene are unsaturated hydrocarbons that have?

A. a single bond

B. a double bond

C. a triple bond

D. an ionic bond

Detailed Solution

In chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.
There is an explanation video available below.
50.

If the relative atomic mass of an element is not a whole number, it can be deduced that the element is?

A. Naturally radioactive

B. abundant in nature

C. a transition metal

D. an isotopic mixture

Detailed Solution

There is an explanation video available below.