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.

856.

How many electrons are present in \(^9_4Be^{2+}\)?

A.

2

B.

4

C.

5

D.

6

Correct answer is A

Neutral Be has 4 electrons but \(Be^{2+}\) means it has lost two electrons from possible four and became a positive ion. 

\(\therefore\) the number of electrons left will be equal to two.

857.

An atom X consist of 6 protons, 6 electrons and 7 neutrons. Which of the following representations of the atom is correct?

A.

136X

B.

137X

C.

196X

D.

197X

Correct answer is A

No explanation has been provided for this answer.

858.

The following atoms of carbon 126C, 136C and 146C can be described as?

A.

Allotropes

B.

Isomers

C.

Isotopes

D.

Isotones

Correct answer is C

No explanation has been provided for this answer.

859.

N2O4(aq) \(\rightleftharpoons\) 2NO2(g) \(\bigtriangleup\)H = +ve

In the reaction above, an increase in temperature will

A.

Increase the reactant production

B.

Increase the value of the equilibrium constant

C.

Shift the equilibrium to the left

D.

Decrease the value of the equilibrium constant

Correct answer is B

No explanation has been provided for this answer.

860.

CH4(g) + CI2(g) \(\to\) CH2CI(s) + HCIg

The major factor that influences the rate of the reaction above is

A.

Concentration

B.

Catalyst

C.

Temperature

D.

Light

Correct answer is D

No explanation has been provided for this answer.