JAMB Chemistry Past Questions & Answers - Page 299

1,491.

Which of the following ions is a pollutant in drinking water even in trace amounts?

A.

Ca2+

B.

Hg2+

C.

Mg2+

D.

Fe2+

Correct answer is B

No explanation has been provided for this answer.

1,493.

Which of the following is arranged in order of increasing electronegativity?

A.

Chlorine, aluminium, magnesium, phosphorus, sodium

B.

sodium, magnesium, aluminium, phosphorus, chlorine

C.

Chlorine, phosphorus, phosphorous, aluminium, magnesium, sodium

D.

Sodium, chlorine, phosphorus, magnesium, aluminium

Correct answer is B

No explanation has been provided for this answer.

1,494.

Which of the following represents the type of bonding present in ammonium chloride molecule?

A.

Ionic only

B.

Covalent only

C.

Ionic and dative covalent

D.

Dative covalent only

Correct answer is C

No explanation has been provided for this answer.

1,495.

The ions X- and Y+ are isoelectronic, each containing a total of 10 electrons.
How many protons are in the nuclei of the neutral atoms of X and Y respectively?

A.

10 and 10

B.

9 and 9

C.

11 and 9

D.

9 and 11

Correct answer is D

X- means one excess electron, hence 9 protons while Y +/- means one deficit electron hence 11 protons X and Y = 9 and 11