When one mole of monoatomic ideal gas at TK undergoes reversible adiabatic change under a constant external pressure of 1 atm changes volume from 1 litre to 2 litre. The final temperature in kelvin would be:

1. T/(2)^2/3                                         

2. T + 2/(3x0.0821)

3. T                                                   

4. T - 3/(2x0.0821)

When two moles of an ideal gas (Cp, m=$\frac{5}{2}$R) heated from 300 K to 600 K at constant pressure the change in entropy of gas ($∆\mathrm{S}$) is:-

(1) $\frac{3}{2}$Rln2

(2) -$\frac{3}{2}$Rln2

(3) 7R ln 2

(4) 5 Rln2

In an adiabatic expansion of an ideal gas-

1. W = –ΔE

2. W = ΔE

3. ΔE = 0

4. W = 0

Equal volumes of monoatomic and diatomic gases at same initial temperature and pressure are mixed. The ratio of specific heats of the mixture (C_p/C_v) will be [AFMC 2002]

(1) 1

(2) 2

(3) 1.67

(4) 1.5

What is the enthalpy change (in kJ) for a process if two moles of an ideal gas are expanded isothermally and reversibly from 1 litre to 10 litre at 300 K?

1. 11.4 kJ

2. –11.4 kJ

3. 0 kJ

4. 4.8 kJ

In an isobaric process, the ratio of heat supplied to the system (dQ) and work done by the system (dW) for diatomic gas is:

1. 1 : 1

2. 7 : 2

3. 7 : 5

4. 5 : 7

One mole of hydrogen gas at ${25}^{\circ }C$ and 1 atm pressure is heated at constant pressure until its volume has doubled. Given that $C_v$ for hydrogen is 3.0 cal deg^-1 mol^-1, the $∆H<mspace\; width="1em"></mspace>$and $∆E$ for this process are-

1. $∆H<mspace\; width="1em"></mspace>$= 1490 cal and $∆E$ = 894 cal

2. $∆H<mspace\; width="1em"></mspace>$= $∆E$= 1490 cal

3. $∆H<mspace\; width="1em"></mspace>$= 894 cal and $∆E$= 1490 cal

4. $∆H<mspace\; width="1em"></mspace>$= $∆E$= 894 cal

One mole of a real gas is subjected to heating at constant volume from$\left(P_1,<mspace\; width="1em"></mspace>V_1,<mspace\; width="1em"></mspace>T_1\right)$ state to $\left(P_2,<mspace\; width="1em"></mspace>V_2,<mspace\; width="1em"></mspace>T_2\right)$ state. Then it is subjected to irreversible adiabatic compression against constant external pressure of P₃ atm till syatem reaches the final state$\left(P_3,<mspace\; width="1em"></mspace>V_3,<mspace\; width="1em"></mspace>T_3\right)$. If the constant volume molar heat capacity of real gas is C_V. Find out correct expression for $∆H$ from state 1 to state 3-

1. $C_v\left(T_3-T_1\right)+\left(P_3{V}_1-P_1{V}_1\right)$

2. $C_v\left(T_2-T_1\right)+\left(P_3{V}_2-P_1{V}_1\right)$

3. $C_v\left(T_2-T_1\right)+\left(P_3{V}_1-P_1{V}_1\right)$

4. $C_p\left(T_2-T_1\right)+\left(P_3{V}_1-P_1{V}_1\right)$

1 mole of NH₃ gas at ${27}^{\circ }C$ is expanded adaibatic condition to make volume 8 times ($\gamma$=1.33). Final temperature and work done respectively are-

1. 150 K, 900 cal

2. 150 K, 400 cal

3. 250 K, 1000 cal

4. 200 K, 800 cal

$C_P-C_V=R$. This R is :

1. Change in K.E.

2. Change in rotational energy

3. work done which system can do on expanding the gas per mol per degree increase in temperature

4. All correct