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.

1,221.

Calculate the mass of chlorine gas which occupies a volume of 1.12 dm\(^3\) a volume of 1.12 dm\(^3\) at s.t.p [Cl = 35.5, 1 mole og gas occupies 22.4 dm\(^3\) at s. t. p ]

A.

1.80g

B.

3.55g

C.

7.10g

D.

15.50g

Correct answer is B

1 mole Cl\(_2\) occupy 22.4dm\(^3\)
i.e 2 x 35.5 → 22.4 ; x → 1. 12
:. x = \(\frac{1.12}{22.4}\) x 2 x 35.5 = 3.55

1,222.

What volume of hydrogen will be produced if 100cm3 of ammonia is completely decomposed at constant temperature and pressure? The equation for reaction is 2NH3(g) → N2(g) + 3H2(g)

A.

50cm3

B.

150cm3

C.

200cm3

D.

300cm3

Correct answer is B

According to the equation 2NH3 → N3 + 3H2
2 x 22400cm3 of ammonia will produce
3 x 22400cm3 of hydrogen
If 100cm3 of NH3 is used.
:. H2 volume = \(\frac{100}{2x22400} x 3x22400
=150cm3

1,223.

Which of the following decreases when a given mass of gas is compressed to half its initial volume?

A.

Average intermolecular distance

B.

Frequency of collisions

C.

Number of molecules present

D.

Atomic radius of each particle

Correct answer is A

No explanation has been provided for this answer.

1,224.

If a metal R forms a compound with the formula R(NO3)2 , the formula of its tetraoxosulphate (IV) is

A.

R(SO4)2

B.

RSO4

C.

R2SO4

D.

R2(SO4)3

Correct answer is B

No explanation has been provided for this answer.

1,225.

An element Y has the electronic configuration 1s22s22p6623p4. To what period does it belong in the periodic table?

A.

3

B.

4

C.

5

D.

6

Correct answer is A

No explanation has been provided for this answer.