Vapour Pressure

Q. If pressure of $C{O}_2$ (real gas) in a container is given by P = $\frac{RT}{2V-b}-\frac{a}{4V^2}$ then mass of the gas in container is

1. 44 gm
2. 11 gm
3. 22 gm
4. 33 gm

Q.

The vapour pressure of a liquid at any temperature is defined as the pressure exerted by the vapour in equilibrium with the liquid at that temperature. T/F

1. False
2. True

Q.
Choose the correct option (s) for a liquid kept in closed vessel at constant temperature:

Q. A vessel A has volume V and a vessel B has volume 2V. Both contain some water which has a constant volume. The pressure in the space above water is $p_a$ for vessel A and $p_b$ for vessel B.

1. $p_a=p_b$
2. $p_a=2p_b$
3. $p_b=2p_a$
4. $p_b=4p_a$

Q. With increase in the volume of a closed system the saturation pressure at the given temperature remains same.

1. False
2. True

Q.

Which of the following changes decrease the vaporise pressure of water kept in a sealed vessel?

(a) Decreasing the quantity of water

(b) Adding salt to the water

(c) Decreasing the volume of the vessel to one-half

(d) Decreasing the temperature of the water

Q.

Pure water vapour is trapped in a vessel of volume 10 $c{m}^3$. The relative humidity is 40 %. The vapour is compressed slowly and isothermally. Find the volume of the vapour at which it will start condensing.

Q.

Pressure exerted by saturated water vapour is called aqueous tension. What correction term will you apply to the total pressure to obtain pressure of dry gas?

Q.

The condition of air in a closed room is described as follows. Temperature = ${25}^0$ C, relative humidity = 60 %, pressure = 104 kPa. If all the water vapour is removed from the room without changing the temperature, what will be the new pressure ? The saturation vapour pressure at ${25}^0$ C = 3.2 kPa.

Q.

The human body has an average temperature of ${98}^0$F. Assume that the vapour pressure of the blood in the veins behaves like that of pure water. Find the minimum atmospheric pressure which is necessary to prevent the blood from boiling. Use figure of the text for the vapour pressures.