Heat Capacity

IMPORTANT

Heat Capacity: Overview

This topic covers concepts, such as, Ratio of Specific Heats, Molar Specific Heat Capacity at Constant Volume, Relation Between Molar and Principal Specific Heat Capacities & Principal Specific Heat Capacity of a Gas at Constant Pressure etc.

Important Questions on Heat Capacity

EASY
IMPORTANT

For a gas of molecular weight M specific heat capacity at constant pressure is r=cpcv

EASY
IMPORTANT

Why the specific heat at a constant pressure is more than that at constant volume.

EASY
IMPORTANT

What is specific heat of gas at constant pressure

EASY
IMPORTANT

At a given temperature, the specific heat of a gas at constant pressure is always greater than its specific heat at constant volume.

EASY
IMPORTANT

Cp-Cv=RM and Cv are specific heats at constant pressure and constant volume respectively. It is observed that, Cp-Cv=a for hydrogen gas and Cp-Cv=b for nitrogen gas. The correct relation between a and b is:

MEDIUM
IMPORTANT

Assertion: The specific heat at constant pressure is greater than the specific heat at constant volume i.e., CP > CV .

Reason: In case of specific heat at constant volume, the whole of heat supplied is used to raise the temperature of one mole of the gas through 1°C while in case of specific of heat at constant pressure, heat is to be supplied not only for heating 1 mole of gas through 1°C but also for doing work during expansion of the gas.

MEDIUM
IMPORTANT

An engine takes in 5 moles of air at 20 °C and 1 atm, and compresses it adiabatically to 110th of the original volume. Assuming air to be a diatomic ideal gas made up of rigid molecules, the change in its internal energy during this process comes out to be x kJ. The value of x to the nearest integer is

MEDIUM
IMPORTANT

The ratio of translational and rotational kinetic energies for 1 mole gas at 200 K temperature is 3: 2 . The internal energy of one mole gas at that temperature is x×102 J. Then value of x is [R=8.3 J/mol-K]

MEDIUM
IMPORTANT

An insulating container of gas has 2 chambers separated by insulating partition. Initially both chambers has equal volume of same gas. Temperature and pressure of left chamber is T1 and P1 and for right chamber is T2 and P2. Now partition is moved towards right by 5 cm maintaining constant pressure on both sides as earlier and after some time partition is removed without doing any work on gas. If final temperature of gas is αP1+βP2P1 T1+P2 T2 find α+β

Question Image

MEDIUM
IMPORTANT

1 mole of a monoatomic ideal gas and 3 mole of a diatomic ideal gas are mixed. If both gasses can not react then what will be γ=CpCv for mixture ? (Cp and Cv are molar specific heat capacities)

MEDIUM
IMPORTANT

An insulated box containing a diatomic gas of molar mass M is moving with velocity v. The box is suddenly stopped. The resulting change in temperature is mv2fR. What will be the value of f?

EASY
IMPORTANT

If SP and SV denote the specific heats of nitrogen gas per unit mass at constant pressure and constant volume respectively, then

EASY
IMPORTANT

The ratio of the molar heat capacities of a diatomic gas at constant pressure to that at constant volume is

EASY
IMPORTANT

A molecule of a gas has six degrees of freedom. Then, the molar specific heat of the gas at constant volume is

HARD
IMPORTANT

One gram mole of an ideal gas A with the ratio of constant pressure and constant volume specific heats γA=53 is mixed with n gram moles of another ideal gas B with γB=75. If the γ for the mixture is 1913, then what will be the value of n?

MEDIUM
IMPORTANT

A rigid triangular molecule consists 8 degrees of freedom. The adiabatic constant γ=CpCv of an ideal gas consisting of such molecules is

EASY
IMPORTANT

Specific heat of an ideal gas at constant volume Cv and at constant pressure Cp are related to universal gas constant are as

MEDIUM
IMPORTANT

 One mole of a an ideal gas is heated at constant pressure through 1K work done by the gas is

EASY
IMPORTANT

An ideal monatomic gas is carried along the cycle ABCDA as shown in the figure. The total heat absorbed in this process is

Question Image 

MEDIUM
IMPORTANT

A gaseous mixture consists of 16 g of helium and 16 g of oxygen. The ratio Cp/Cv of the mixture is