JAMB Past Questions and Answers - Page 1711

8,551.

From the diagram above, find the amount of solute deposited when 200 cm33 of the solution is cooled from 55°C to 40°C.

A.

0.10 mole

B.

0.20mole

C.

0.01 mole

D.

0.02 mole

Correct answer is B

From the diagram,

55°C = 7 moles; 40°C = 6 moles.

Amount of solute deposited = 7 - 6 = 1 mole.

1000 cm\(^3\) = 1 mole

200 cm\(^3\) = x

x = \(\frac{200 \times 1}{1000}\)

= 0.20 mole.

8,552.

The arrangement of particles in crystal lattices can be studied using

A.

X - rays

B.

γ - rays

C.

α - rays

D.

β - rays

Correct answer is A

No explanation has been provided for this answer.

8,553.

The molecular lattice of iodine is held together by

A.

dative bond

B.

metallic bond

C.

hydrogen bond

D.

van der Waal's forces

Correct answer is D

No explanation has been provided for this answer.

8,554.

An isotope has an atomic number of 15 and a mass number of 31. The number of protons it contain is

A.

16

B.

15

C.

46

D.

31

Correct answer is B

No explanation has been provided for this answer.

8,555.

The relative atomic mass of a naturally occurring lithium consisting of 90% \(^7 _3\)Li and \(^6 _3\)10% Li is

A.

6.9

B.

7.1

C.

6.2

D.

6.8

Correct answer is A

R.A.M = m\(_1 \alpha_1\) + m\(_2 \alpha_2\)

= 7(90/100) + 6(10/100)

= 6.3 + 0.6

= 6.9