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.

3,521.

Pollution of underground water by metal ions is very likely in the soil that has high

A.

acidity

B.

alkalinity

C.

chloride content

D.

nitrate content

Correct answer is D

Trioxonitrate(v) salts are generally d only soluble salts of some metals.All trioxonitrate(v) salts r soluble in water. Therefore d metal ions found in underground water, are derived mostly 4rm d soluble nitrates (Trioxonitrate(v) salts) of those metals.

3,522.

Hardness of water is caused by the presence of ions of

A.

magnesium and silver

B.

cacium and magnesium

C.

sodium and potassium

D.

calcium and sodium

Correct answer is B

No explanation has been provided for this answer.

3,523.

Which of the following mixture of gases is likely to burn in flame

A.

neon and hydrogen

B.

nitrogen and helium

C.

helium and neon

D.

neon and nitrogen

Correct answer is A

No explanation has been provided for this answer.

3,524.

Chlorine consisting of two isotopes of mass number 35 and 37 in the ratio 3:1 has an atomic mass of 35.5. Calculate the relative abundance of the isotopes of mass number 37

A.

20

B.

25

C.

60

D.

75

Correct answer is B

Let the relative abundance of oxygen with mass 37 be x%
∴ The relative abundance of the isotope of mass 35 = (100 - x)%. Total mass of isotopes of mass 37 = 37x, while that of 35 = 35(100 - x)
∴ Total mass of the 100 atoms
= 37x + 35(100 - x) = 35.5
= 37x + 3500 - 35x = 35.5
∴ Mean mass of chlorine atom = (2x + 3500)/100 = 35.5
2x + 3500 = 3550; x = 50/2 = 25

3,525.

The property of chlorine which causes hydrogen chloride to be more ionic than the chlorine molecules is its

A.

electrovalency

B.

electron affinity

C.

electropositivity

D.

electronegativity

Correct answer is D

No explanation has been provided for this answer.