JAMB Chemistry Past Questions & Answers - Page 305

1,521.

Equal volumes of CO,SO2, NO2 and H2S were released into a room at the same point and time. Which of the following gives the order of diffusion of the gases to the opposite corner of the room?
(S = 32, C = 12, O = 16, N = 14, H = 1)

A.

CO, SO2,NO2,H2S

B.

SO2,NO2,H2S,CO

C.

CO,H2S,SO2,NO2

D.

CO,H2S,NO2,SO2

Correct answer is D

- At a constant temperature and pressure, the rate lof diffusion of a gas is inversely proportional to the rate of its relative molecular mass.

- The higher the RMM of a gas the Lower the rate of diffusion and vice versa

- Hence; CO,H2S,NO2,SO2 will be the order of diffusion.

1,522.

The volume occupies by 1.58g of a gas at s.t.p is 500cm3. What is the relative molecular mass of the gas?

(G.M.V at s.t.p = 22.40dm3)

A.

28

B.

32

C.

44

D.

71

Correct answer is D

500cm3 = 1.58g

=22400cm = (1.58g)/(500cm3) χ 22400cm3) = 70.78 g
= 71g

1,523.

If a gas occupies a container of volume 146 cm3 at 18°C and 0.97`atm, its volume 146cm3 at s.t.p is?

A.

133

B.

146

C.

266

D.

292

Correct answer is A

V1 = 146cm3 T1 = 273 + 118 = 291 k

P1 = 0.971 atmosphere

V2 = ? T2 = 273K P2 = 1 atom

V2 = (0.971 atom χ 146cm3 χ 273k)/(1atm χ 291k) = 132997 0r = 133cm3

1,524.

Which of the following is formed when maltose reacts with concentrated tetraoxosulphate (VI) acid ?

A.

Carbon (IV) oxide

B.

Coal tar

C.

Charcoal

D.

Toxic fumes

Correct answer is C

No explanation has been provided for this answer.