# Heat Capacity

## Trending Questions

**Q.**

Two ideal polyatomic gases at temperatures ${T}_{1}$ and ${T}_{2}$ are mixed so that there is no loss of energy. If ${F}_{1}$_{ }and ${F}_{2}$, ${m}_{1}$_{ }and ${m}_{2}$, ${n}_{1}$ and ${n}_{2}$ be the degrees of freedom, masses, the number of molecules of the first and second gas respectively, the temperature of the mixture of these two gases is:

$\frac{{n}_{1}{F}_{1}{T}_{1}+{n}_{2}{F}_{2}{T}_{2}}{{n}_{1}{F}_{1}+{n}_{2}{F}_{2}}$

$\frac{{n}_{1}{F}_{1}{T}_{1}+{n}_{2}{F}_{2}{T}_{2}}{{F}_{1}+{F}_{2}}$

$\frac{{n}_{1}{F}_{1}{T}_{1}+{n}_{2}{F}_{2}{T}_{2}}{{n}_{1}+{n}_{2}}$

$\frac{{n}_{1}{T}_{1}+{n}_{2}{T}_{2}}{{n}_{1}+{n}_{2}}$

**Q.**

Gas at a pressure P0, in contained is a vessel. If the masses of all the molecules are halved and their speeds are doubled, the resulting pressure P will be equal to

4P0

2P0

P0

P02

**Q.**Which of the following graphs correctly represents the variation of molar heat capacity at constant volume with temperature for an ideal monoatomic gas?

**Q.**

What will be the amount of mercury, if the specific heat capacity of mercury is $0.14J{g}^{-1}\xc2\xb0{C}^{-1}$ and heat capacity is $140J{g}^{-1}\xc2\xb0{C}^{-1}$?

$1kg$

$100g$

$10g$

$200g$

**Q.**One mole of a monoatomic gas is heated at a constant pressure of 1 atm from 0 K to 100 K. If the gas constant R = 8.32 J mol−1 K−1, the change in internal energy of the gas is approximately

- 2.3 J
- 46 J
- 8.67 × 103 J
- 1.25 × 103 J

**Q.**The molar heat capacity of a gas at constant volume is 5 cal mol−1 K−1. Find the value of γ for the gas if the gas constant, R=2 cal mol−1K−1.

- 1.66
- 1.4
- 1.33
- 1.8

**Q.**For an isobaric process involving an ideal gas, the ratio of heat supplied and work done by the system (gas) is

- γ−1γ
- γ
- γγ−1
- 1

**Q.**

Consider a gas with density ρ and ¯c as the root mean square velocity of its molecules contained in a volume. If the system moves as whole with velocity v, then the pressure exerted by the gas is

13ρ¯c2

13ρ(c+v)2

13ρ(¯c−v)2

13ρ(c−2−v)2

**Q.**A sample of an ideal gas has diatomic molecules at a temperature at which effective degree of freedom is 5. Under the action of radiation, each molecule splits into two atoms. If the ratio of the number of dissociated molecules to the total number of molecules is α, then find the ratio of molar specific heat capacities (γ=CPCV).

- 2α+5
- 5α+2
- 1+2α+5
- 1+5α+2

**Q.**70 cal of heat is required to raise the temperature of 2 moles of an ideal gas at constant pressure from 30∘ C to 35∘ C. The amount of heat required to raise the temperature of the same gas through same range of temperature (30∘ C to 35∘ C) at constant volume is

Given (γ=7/5)

- 30 cal
- 50 cal
- 70 cal
- 90 cal

**Q.**An ideal monoatomic gas at temperature 27∘C and pressure 106 N/m2 occupies 10 L volume. 10, 000 cal of heat is added to the system without changing the volume. Calculate the change in temperature of the gas. Given:R=8.31 J/mol-K and J=4.18 J/cal

- 500 K
- 833 K
- 300 K
- 0 K

**Q.**Two moles of a monoatomic gas is mixed with three moles of a diatomic gas. The molar specific heat of the mixture at a constant volume is

- 1.6R
- 2.1R
- 6.25R
- 3.6R

**Q.**The half life of a radioactive substance is \(13\) years. The decay constant is,

**Q.**The half life of a radioactive substance is 13 years. The decay constant is,

- 1.96×10−9 sec−1
- 1.29×10−7 sec−1
- 1.69×10−10 sec−1
- 1.69×10−9 sec−1

**Q.**Two moles of helium (He) are mixed with four moles of hydrogen (H2). The molar heat capacity of the mixture at constant pressure is

- 19R6
- 17R6
- 15R6
- 3R2

**Q.**When an ideal monoatomic gas is heated at constant pressure, the fraction of heat energy supplied which increases the internal energy of gas is

- 2/5
- 3/5
- 3/7
- 3/4

**Q.**One mole of a monoatomic ideal gas undergoes the process A→B in the given P−V diagram. The specific heat for this process is

- 3R/2
- 13R/6
- 5R/2
- 2R

**Q.**A gaseous mixture enclosed in a vessel consists of one gram mole of a gas A with γ=53 and some amount of gas B with γ=75 at a temperature T. The gases A and B do not react with each other and are assumed to be ideal. Find the number of moles of the gas B if γ for the gaseous mixture is (1913).

- 1
- 2
- 3
- 4

**Q.**Suppose the distance between the atoms of a diatomic gas remains constant. Its specific heat at constant volume per mole is

- 5R2
- 3R2
- 7R2
- 9R2

**Q.**

The value of Cv for one mole of neon gas is

12R

32R

52R

72R

**Q.**Specific heat capacity at constant volume of one mole diatomic ideal gas is

- 2R
- 1.5R
- R
- 2.5R

**Q.**

Gas at a pressure P0, in contained is a vessel. If the masses of all the molecules are halved and their speeds are doubled, the resulting pressure P will be equal to

4P0

2P0

P0

P02

**Q.**If for a gas (RCV)=0.67, then the

molecules of gas are

- diatomic
- monoatomic
- triatomic
- polyatomic

**Q.**Which of the following is the incorrect statement about the molar heat capacity of an ideal gas system?

- Molar heat capacity at no exchange condition, CA=0
- Molar heat capacity at constant temperature, CT→∞
- Molar heat capacity at constant pressure, Cp=γRγ−1
- Molar heat capacity at constant volume, Cv=Rγ

**Q.**One mole of an ideal monoatomic gas is initially at 500 K. If 300 J of heat is added at constant volume, the final temperature of the gas is

(Assume R=8 J/mol K)

- 525 K
- 550 K
- 600 K
- 625 K

**Q.**A gaseous mixture enclosed in a vessel of volume 2 m3 consists of 2 moles of a gas A with γA=CPCV=53, another gas B with γB=75 at a temperature 43∘C. The gram molecular weights of A & B are 32 gm and 4 gm respectively. Assume gases to be non - reacting. The gaseous mixture follows PV20/14=constant in adiabatic process. Find the number of moles of the gas B in the gaseous mixture.

- nB=4 moles
- nB=2 moles
- nB=7 moles
- nB=10 moles

**Q.**

Molar specific heat at constant volume Cv for a monoatomic gas is

32R

52R

3R

2R

**Q.**A gas at pressure p is adiabatically compressed so that its density becomes twice that of initial value. Given that γ=CP/Cv=7/5 what will be the final pressure of the gas?

- 2 p
- 75 p
- 2.63 p
- p

**Q.**Specific heat capacity at constant volume of one mole diatomic ideal gas is

- 2R
- 1.5R
- R
- 2.5R

**Q.**The molar heat capacity of a gas at constant volume is 5 cal mol−1 K−1. Find the value of γ for the gas if the gas constant, R=2 cal mol−1K−1.

- 1.66
- 1.4
- 1.33
- 1.8