2021 - JAMB Chemistry Past Questions & Answers - page 1

1

What is the common name for the following compound (CH\(_{3}\))\(_{2}\) CH CH\(_{2}\) -Br

A

Isobutyl bromide

B

Methyl bromide

C

propyl bromide

D

Butyl bromide

CORRECT OPTION: a

The common name: Isobutyl bromide

The IUPAC name: 1-Bromo-2-methylpropane

Formula: C\(_4\)H\(_9\)Br

2

The enzyme that converts glucose to ethyl alcohol is?

A

maltase

B

zymase

C

Diatase

D

Invertase

CORRECT OPTION: b

Zymase is an enzyme complex that catalyzes the fermentation of sugar into ethanol and carbon dioxide. It occurs naturally in yeasts. More

3

The scientist who stated that matter can be converted into energy is? 

A

Boyle

B

Lavoiser

C

Avogadro

D

Einstein

CORRECT OPTION: d

Albert Einstein's theory of special relativity defines the relationship between mass and energy, E = mc^2

4

What is the IUPAC name for the following compound? HC\(\equiv\)CCH\(_{3}\)

A

Acetylene

B

Methylacetylene

C

Butanol

D

Decanoic acid

CORRECT OPTION: b

Propyne (methylacetylene), an alkyne with the chemical formula HC\(\equiv\)CCH\(_{3}\)

5

What is the chemical name for the compound CuCO\(_{3}\)?

A

Copper (iii) carbonate

B

Copper (ii) carbonate

C

Copper (i) carbonate

D

Copper

CORRECT OPTION: b

Copper(II) carbonate or cupric carbonate. Chemical compound formula CuCO\(_{3}\) 

6

A 'breath test' used by traffic police to check drunken driving uses?

A

Tumeric on filter paper

B

Silica gel coated with saliva nitrate

C

Potassium permanganate-sulphuric acid

D

Potassium dichromatic-sulphuric acid

CORRECT OPTION: d

A breathalyzer or breathalyser is a device used for estimating blood alcohol content (BAC), or to detect viruses or diseases from a breath sample.

7

Which one of the following is not a mixture?

A

Air

B

Mercury

C

Milk

D

Cement

CORRECT OPTION: b

A  mixture is a material made up of two or more different chemical substances which are not chemically combined. 

Mercury with the chemical symbol Hg and the atomic number 80 is an element that has not reacted with another substance. When mercury reacts with another substance, it forms a compound, such as inorganic mercury salts.

8

Which of the following is a non-metal that remains liquid at room temperature?

A

Chlorine

B

Phosphorus

C

Bromine

D

Helium

CORRECT OPTION: c

Bromine, with the symbol Br and atomic number 35, is the third-lightest halogen. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour.

9

Which of the following are chemical changes? 

I. cooking of food
II. digestion of food
III. freezing of water
IV. water is heated up

A

I and II

B

I, II, and III

C

III and IV

D

all of the above

CORRECT OPTION: a
10

The atomic weight of nitrogen is?

A

10

B

12

C

14

D

16

CORRECT OPTION: c

Atomic weight or Relative Atomic Mass is the ratio of the average mass of a chemical element's atoms to some standard, defined as the weighted average of the masses of the isotopes of an element compared to 1/12 of the mass of the carbon-12 atom. The formula for relative atomic mass is ∑isotope mass x isotope abundance / 100.

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