JAMB Chemistry Past Questions & Answers - Page 88

436.

The drying agent suitable for drying ammonia is

A.

Calcium Chloride

B.

Calcium Oxide

C.

Phosphorus(V) Oxide

D.

Concentrated H2SO4

Correct answer is B

No explanation has been provided for this answer.

437.

The number of electronic shells contained in an atom with electron configuration 1s22s22p63s23p64s2 is

A.

3

B.

2

C.

4

D.

5

Correct answer is C

No explanation has been provided for this answer.

438.

Ethanol is soluble in water due to the presence of a

A.

Carbonyl group

B.

Hydroxyl group

C.

Phenyl group

D.

Methyl group

Correct answer is B

No explanation has been provided for this answer.

439.

Diamond cannot be used

A.

In making bicycle chains

B.

As abrasives

C.

In cutting glass and metals

D.

As dies for drawing wires

Correct answer is A

No explanation has been provided for this answer.

440.

What volume of 0.5M H2SO4 will exactly neutralize 20cm3 of 0.1M NaOH Solution?

A.

2.0cm 3

B.

5.0cm 3

C.

6.8cm 3

D.

8.3cm 3

Correct answer is A

The balanced equation is given as:

\(H_{2}SO_{4} + 2NaOH \to Na_{2}SO_{4} + 2H_{2}O\)

Molarity of \(NaOH = 0.1M\)

Volume of \(NaOH = 20cm^{3}\)

Molarity of \(H_{2}SO_{4} = 0.5M\)

mol NaOH = \(0.1 \times 20cm^{3} = 2molNaOH\)

⇒ \(2mol NaOH \times \frac{1mol H_{2}SO_{4}}{2mol NaOH} = 1 mol H_{2}SO_{4}\)

\(volume of H_{2}SO_{4} = \frac{mole of H_{2}SO_{4}}{molarity of H_{2}SO_{4}}\)

= \(\frac{1 mole}{0.5 M} = 2cm^{3} H_{2}SO_{4}\)