Class 11th

This is a short answer type question as classified in NCERT Exemplar

The CO₂ gas cannot be liquified at the 32°C and 80 atm pressure as the given temperature and pressure are above critical temperature (T_c) and critical pressure (p_c) which are 30.98°C and 73 atm respectively.

This is a short answer type question as classified in NCERT Exemplar

(i) The value of Z for an ideal gas is 1. 

(ii) For real gas, the value of Z > 1 above Boyle's temperature 

This is a short answer type question as classified in NCERT Exemplar

The assumption of kinetic theory of gases that there is no force of attraction between the molecules of a gas is applicable for real gases. The evidence for this is  that the real gas can be liquified at high pressure and low temperature. This proves that there is force of attraction between the molecules of gas.

This is a short answer type question as classified in NCERT Exemplar

The two intermolecular forces that exist between HF molecules in liquid state are hydrogen bonding (as F is a highly electronegative atom) and  dipole-dipole interaction (as HF is a polar molecule).

This is a short answer type question as classified in NCERT Exemplar

The energy which arises due to motion of atoms or molecules in a body is known as thermal energy and the average kinetic energies of all the molecules increases with increases in temperature.

This is a short answer type question as classified in NCERT Exemplar

Water and alcohol are polar  molecules which have high electronegative O atm  so they  have hydrogen bonding along with dipole-dipole interaction.   Hexane is a nonpolar molecule that has London dispersion force  which is a weak force between the molecules. Water has stronger H-bonding than alcohol. So, the order of attractive force will be:

Hexane  <   Alcohol  <  Water

More attractive forces between the molecules, the greater the  magnitude of surface tension of the liquid.

This is a short answer type question as classified in NCERT Exemplar

The assumption of the kinetic theory of gases which states that- “ there is no force of attraction between the molecules of a gas. ” is a correct statement. Ideal gas has minimum force of attraction between the molecules and hence, it cannot be liquified. Liquefaction of a gas can only  be done when the force of attraction between the molecules increases, which is not possible for an ideal gas.

This is a short answer type question as classified in NCERT Exemplar

Unit of R depends on the  units of  p, V and T are measured, We know,   R=pVnT  Now, let's say, the  pressure is measured in Pascal, per mole volume is measured in m³ and temperature is measured in Kelvin,   then. Units of 'R' are Pa m³K^-1 mol^-1. Also, R is work done per mole per kelvin. It's unit is J K^-1 mol^-1 (Joule is the unit of work done).