Chemistry Question Bank

Gases possess characteristic critical temperature which depends upon the magnitude of intermolecular forces between the particles. Following are the critical temperatures of some gases Gases : H2 He O2 N2 Critical tem…

Assertion : The pressure of a gas is inversely proportional to the volume at constant temperature and n. Reason : The gas volume is directly proportional to n at constant temperature and pressure.

Assertion :For a given amount of an ideal gas, a plot of pressure (p) versus (1/V) is a straight line at a constant temperature. Reason :A given amount of an ideal gas at a constant temperature obeys Boyle’s law.

Assertion: According to Charles’ law, for a give amount of an ideal gas at a given pressure, plot of gas volume versus absolute temperature is a straight line passing through origin. Reason: Gaseous volume never vanis…

Assertion: A lighter gas diffuses more rapidly than a heavier gas. Reason: At a given temperature, the rate of diffusion of a gas is inversely proportional to the density.

Assertion :Kinetic energy and momentum of ideal gas molecules are conserved during intermolecular collision. Reason :Collision among real gas molecules is inelastic.

Assertion :According to kinetic theory of gases, gas molecules occupy some space. Reason :Gases can be liquefied and solidified.

Assertion: For a real gas, the gas pressure is always less than the pressure calculated from kinetic theory of gases. Reason: In kinetic theory, both molecular volumes and intermolecular attractions were ignored.

Assertion: Compressibility factor (Z) for non- ideal gases may be less than or greater than 1. Reason: Non-ideal gases always exert higher pressure than expected.

Assertion:CH4, CO2 has value of Z (compressibility factor) less than one at 0ºC. Reason :Z < 1 is due to the attractive forces dominate among the molecules.

Assertion :Gases do not liquefy above their critical temperature, whatever the high pressure is applied. Reason :Above critical temperature, molecular speed is high and intermolecular force cannot hold the molecules t…

Assertion :Above critical temperature liquid state cannot be observed. Reason :Above critical temperature, the average kinetic energy of a molecule is always greater than the maximum kinetic energy a molecule can poss…

A flask containing air (open to atmosphere) is heated from 300 K to 500 K. The percentage of air escaped to the atmosphere is nearly

Which of the following is a correct plot of the volume of fixed amount of ideal gas as a function of temperature (at constant pressure) ? (a) (b) (c) (d)

Five grams each of the following gases at 87oC and 750 mm pressure are taken. Which of them will have the least volume ?

For V versus T plot at constant pressure P1 and P2 for an ideal gas is given in adjoining figure. Which of the following relation is correct ?

Among the plots of P versus V, as given below, which one corresponds to Boyle’s law ? (a) (b) (c) (d)

An open flask contains air at 27oC temperature and one atm pressure. The flask is heated to 127 oC at the same pressure. What fraction of the original air will remain in the flask?

Three different gases X, F and Z of molecular masses 2, 16 and 64 were enclosed in a vessel at constant temperature till equilibrium is reached. Which of the following Statement is correct? (Kerala CEE 2011)

When r, P and M represent rate of diffusion, pressure and molecular mass, respectively, then the ratio of the rates of diffusion (rA/rB) of two gases A and B, is given as (WB JEE 2011)

The molecular velocity of any gas is (WB JEE 2011)

a and b are van der Waals constants for gases. Chlorine is more easily liquefied than ethane because (KCET 2011)

If the temperature changes from 27°C to 127°c relative percentage change in RMS velocity is (OJEE 2010)

Given, RMS velocity of hydrogen at 300 K is 1.9 × 103 m/s. The RMS velocity of oxygen at 1200 K will be (OJEE 2010)

At what temperature, the RMS velocity of gas present at 50°C will be doubled? (OJEE 2010)