JAMB Chemistry Past Questions & Answers - Page 402

2,006.

Steam changes the colour of anhydrous cobalt (II) chloride from

A.

blue to pink

B.

white to red

C.

white to green

D.

blue to white

Correct answer is A

No explanation has been provided for this answer.

2,007.

The property which makes alcohol soluble in water is the

A.

boiling point

B.

hydrogen bonding

C.

ionic character

D.

covalent nature

Correct answer is B

No explanation has been provided for this answer.

2,008.

The furring of kettles is caused by the presence in the water of?

A.

Calcium tetraoxosulphate (VI)

B.

Calcium hydrogentrioxocarbonate (IV)

C.

Calcium hydroxide

D.

Calcium trioxocarbonate (IV)

Correct answer is D

The furring of kettles or boilers - this is as a result of the decomposition of \(Ca(HCO_3)_2\) into \(CaCO_3\), and this\(CaCO_3\) coats the inside of a kettle or boiler used in heating water containing dissolved \(Ca(HCO_3)_2\).

2,009.

The substance least considered as a source of environmental pollution is

A.

Lead compounds

B.

Organophosphorous compounds

C.

Silicate minerals

D.

Uranium

Correct answer is C

No explanation has been provided for this answer.

2,010.

25cm3 of a 0.2 mol dm3 solution of Na2CO3 requires 20 cm3 of a solution of HCl for neutralization. The concentration of the HCl solution is

A.

0.5 mol dm3

B.

0.6 mol dm3

C.

0.2 mol dm3

D.

0.4 mol dm3

Correct answer is A

No explanation has been provided for this answer.