JAMB Chemistry Past Questions & Answers - Page 331

1,651.

Moving from left to right across a period, the general rise in the first ionization energy can be attributed to the?

A.

decrease in nuclear charge

B.

increase in nuclear charge

C.

decrease in screening effect

D.

increase in screening effect

Correct answer is B

No explanation has been provided for this answer.

1,652.

The volume of a given gas is V cm3 P mm Hg. what is the new volume of the gas if the pressure is reduced to half at constant temperature?

A.

4 V cm3

B.

2 V cm3

C.

V/2 cm3

D.

V cm3

Correct answer is B

No explanation has been provided for this answer.

1,653.

The droplets of water observed around a bottle of milk taken out of the refrigerator is due to the fact that the?

A.

water vapour in the air around the bottle gains some energy from the bottle

B.

temperature of the milk drops as it loses heat into the surroundings

C.

saturated vapour pressure of the milk is equal to the atmospheric pressure

D.

water vapour in the air around the bottle loses some of its energy to the bottle

Correct answer is D

When a cold milk bottle is taken out from the refrigerator, the water vapor in the air around the bottle comes in contact with the cold surface of the bottle and gets condensed.

1,654.

Calculate the percentage by mass of nitrogen in calcium trioxonitrate (V)
[Ca = 40, N = 14, O = 16]

A.

8.5%

B.

13.1%

C.

17.1%

D.

27.6%

Correct answer is C

No explanation has been provided for this answer.

1,655.

Which of the following is an example of a mixture?

A.

Common salt

B.

Blood

C.

Sand

D.

Washing soda

Correct answer is B

The Blood is a mixture which consists of water, proteins, fats, oil, sugar, vitamins, hormones, enzymes,e\ etc