## Kinetic Theory Questions and Answers Part-19

1. Which of the following formulae is wrong
a) $C_{V}=\frac{R}{\gamma-1}$
b) $C_{P}=\frac{\gamma R}{\gamma-1}$
c) $C_{P}\diagup C_{V}=\gamma$
d) $C_{P}- C_{V}=2R$

Explanation: This formula is wrong -> $C_{P}- C_{V}=2R$

2. For hydrogen gas $C_{P}- C_{V}=a$    and for oxygen gas $C_{P}- C_{V}=b$   . So the relation between a and b is given by
a) $a =16b$
b) $b =16a$
c) $a =4b$
d) $a =b$

Explanation: $a =b$

3. For a gas the difference between the two specific heats is 4150 J/kg K. What is the specific heats at constant volume of gas if the ratio of specific heat is 1.4
a) 8475 J / kg K
b) 5186 J / kg K
c) 1660 J / kg K
d) 10375 J / kg K

Explanation: 4. The quantity of heat required to raise one mole through one degree Kelvin for a monoatomic gas at constant volume is
a) $\frac{3}{2}R$
b) $\frac{5}{2}R$
c) $\frac{7}{2}R$
d) 4 R

Explanation: The quantity of heat required to raise one mole through one degree Kelvin for a monoatomic gas at constant volume is $\frac{3}{2}R$

5. The specific heat relation for ideal gas is
a) $C_{P}+ C_{V}=R$
b) $C_{P}- C_{V}=R$
c) $C_{P}\diagup C_{V}=R$
d) $C_{V}\diagup C_{P}=R$

Explanation: The specific heat relation for ideal gas is $C_{P}- C_{V}=R$

6. The specific heat of 1 mole of an ideal gas at constant pressure $\left(C_{P}\right)$  and at constant volume $\left(C_{V}\right)$  which is correct
a) $C_{P}$ of hydrogen gas is $\frac{5}{2}R$
b) $C_{V}$ of hydrogen gas is $\frac{7}{2}R$
c) $H_{2}$ has very small values of $C_{P}$  and $C_{v}$
d) $C_{P} - C_{v}$ = 1.99 cal/mole-K for $H_{2}$

Explanation: $C_{P} - C_{v}$ = 1.99 cal/mole-K for $H_{2}$

7. What is the ratio of specific heats of constant pressure and constant volume for $NH_{3}$
a) 1.33
b) 1.44
c) 1.28
d) 1.67

Explanation: Ratio of specific heats of constant pressure and constant volume for $NH_{3}$ is 1.33

8. If two moles of diatomic gas and one mole of mono atomic gas are mixed then the ratio of specific heats is
a) $\frac{7}{3}$
b) $\frac{5}{4}$
c) $\frac{19}{13}$
d) $\frac{15}{19}$

Explanation: If two moles of diatomic gas and one mole of mono atomic gas are mixed then the ratio of specific heats is $\frac{19}{13}$

9. One mole of ideal monoatomic gas $\left(\gamma=5\diagup3\right)$   is mixed with one mole of diatomic gas $\left(\gamma=7\diagup5\right)$   . What is $\gamma$ for the mixture? $\gamma$ denotes the ratio of specific heat at constant pressure, to that at constant volume
a) 3/2
b) 23/15
c) 35/23
d) 4/3 10. A gaseous mixture contains equal number of hydrogen and nitrogen molecules. Specific heat measurements on this mixture at temperatures below 100 K would indicate that the value of $\gamma$ (ratio of specific heats) for this mixture is