Work done in Isothermal Irreversible Process

Q. Two moles of an ideal gas is expanded isothermally and reversibly from 1 litre to 10 litre at 300 K. The enthalpy change ( in kJ) for the process is

1. 0 kJ

2. 4.8 kJ

3. −11.4 kJ

4. 11.4 kJ

Q. The change in entropy of 2 moles of an ideal gas upon isothermal expansion at 243.6 K from 20 litre until the pressure becomes 1 atm, is

1. 1.385 cal/K

2. − 1.2 cal/K

3. 1.2 cal/K

4. 2.77 cal/K

Q. 36. An ideal gas expands isothermally from a volume V1 to V2 and then compressed to original volume V1 adiabatically. Initial pressure is P1 and final pressure is P3. The total work done is W. Then

Q. Calculate entropy change when $10$ moles of an ideal gas expands reversibly and isothermally from an initial volume of $10$ litre to $100$ litre at $300K$.

Q. 10 litres of a monoatomic ideal gas at $0^{o}C$ and 10 $atm$ pressure is suddenly exposed to 1 $atm$ pressure and the gas expands adiabatically against this constant pressure to maximum possible volume. The final temperature and volume of the gas respectively are

Q. Assertion :Statement-I : Entropy change in reversible adiabatic expansion of an ideal gas is zero.
Because Reason: Statement-II : The increase in entropy due to volume increase just compensate the decrease in entropy
due to fall in temperature.

1. Statement-I is true, Statement-II is true ; Statement-II is correct explanation for Statement-I.
2. Statement-I is true, Statement-II is true ; Statement-II is not a correct explanation for Statement-I.
3. Statement-I is true, Statement-II is false.
4. Statement-I is false, Statement-II is true.

Q. Under isothermal conditions, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is:
(Given that 1 L bar = 100 J)

1. -30 J
2. 5 kJ
3. 25 J
4. 30 J

Q. Match the following
$\begin{array}{cc}ListI& ListII\\ A.\text{Reversible isothermal expansion}& \left(p\right)w=-R{P}_{ext}\frac{[T_2{P}_1-T_1{P}_2]}{P_1{P}_2}\\ B.\text{Irreversible isothermal expansion}& \left(q\right)w=\frac{R}{\gamma -1}[T_2-T_1]\\ C.\text{Reversible adiabatic expansion}& \left(r\right)w=-P_{ext}(V_2-V_1)\\ D.\text{Irreversible adiabatic expansion}& \left(s\right)w=-nRTlog\left(\frac{V_2}{V_1}\right)\end{array}$

1. A - (r), B - (s). C-(q), D - (p)
2. A - (s), B - (r). C-(p), D - (q)
3. A - (s), B - (r). C-(q), D - (p)
4. A - (p), B - (r). C-(q), D - (s)

Q. 110.1 L of an ideal gas( Y=1.5) at 300 K is suddenly compressed to half of its original volume.Original pressure is 100 kPa.The gas is now expanded isothermally to achieve its original volume of 1 L.Calculate the work done by the gas?

Q. Two moles of an ideal gas is expanded isothermally and reversibly from $1\text{L}$ to $10\text{L}$ at $300\text{K}$. The internal energy change $\left(\text{in kJ}\right)$ for the process is

1. 11.4 kJ
2. -11.4 kJ
3. 0 kJ
4. 4.8 kJ

Q. One mole of a gas is expanded from ($1L,10atm,300K$) to ($4L,5atm,300K$) against a constant external pressure of $1atm$. The heat capacity of gas is $50J{/}^{o}C.$Then the work done during the process is:
(Take $1Latm\simeq 100J$)

1. $-300J$
2. $-600J$
3. $300J$
4. $-100J$

Q. If a gas at $10atm$ and $300K$ expands against a constant external pressure of $2atm$ from a volume of 10 litres to 20 litres, the amount of work done is:
Given: 1 L.atm = 101.3 J

1. $17$L.atm
2. $10$ L.atm
3. $-2026$J
4. $2026J$

Q. If a gas at $5atm$ and $373K$ expands against a constant external pressure of $1atm$ from a volume of 2 litres to 10 litres, the amount of work done is:
(Given: $1L.atm=101.3J$)

1. $-402J$
2. $-525.3J$
3. $-212.8J$
4. $-810.4J$

Q. If one mole of an ideal gas $(C_{p,m}=\frac{5}{2}R)$ is expanded isothermally at 300 K, until it's volume is tripled, then, change in entropy of gas is :

1. $\infty$
2. $\frac{5}{2}R\ln 3$
3. $0$
4. $R\ln 3$

Q. An ideal gas undergoing expansion in vaccum shows
1) deltaE= 0
2) W=0
3 q=0
Why? Give explaination.

Q. Match the following
$\begin{array}{cc}ListI& ListII\\ A.\text{Reversible isothermal expansion}& \left(p\right)w=-R{P}_{ext}\frac{[T_2{P}_1-T_1{P}_2]}{P_1{P}_2}\\ B.\text{Irreversible isothermal expansion}& \left(q\right)w=\frac{R}{\gamma -1}[T_2-T_1]\\ C.\text{Reversible adiabatic expansion}& \left(r\right)w=-P_{ext}(V_2-V_1)\\ D.\text{Irreversible adiabatic expansion}& \left(s\right)w=-2.303nRTlo{g}_{10}{V}_2/V_1\end{array}$

1. A - (s), B - (r). C-(q), D - (p)
2. A - (s), B - (r). C-(p), D - (q)
3. A - (r), B - (s). C-(q), D - (p)
4. A - (p), B - (r). C-(q), D - (s)

Q. Two identical samples of a gas are allowed to expand (i) isothermally (ii) adiabatically. The magnitude of work done is

1. More in the isothermal process
2. More in the adiabatic process
3. Equal in both processes
4. Dependent on atomicity of gas

Q. a very good evening to RESPECTED EXPERTS
A GAS EXPANDS ISOTHERMALLY from 10 dm3 to 20 dm3 at 27 degree celsius and work obtained is 4.620 kj. calculate the number of mols of the gas.

Q. calculate the work done in joule when 3 moles of an ideal gas expand isothermally and reversibly
from 10 atm to 1 atm. what will be the work done if the expansion is against constant pressure of 1atm.

Q. Calculate the heat involved in a reaction for the isothermal expansion of one mole of a ideal gas at ${27}^o$ C from a volume of 50 L to 100 L.

1. $Q$ = 159 J
2. $Q$ = 2294 J
3. $Q$ = 1729 J
4. $Q$ = 2197 J

Q. Two moles of an ideal gas is expanded isothermally and reversibly from $1\text{L}$ to $10\text{L}$ at $300\text{K}$. The internal energy change $\left(\text{in kJ}\right)$ for the process is

1. 11.4 kJ
2. -11.4 kJ
3. 0 kJ
4. 4.8 kJ

Q. 2 mole of a ideal gas at 2 bar and 27 deg celcius expands isothermally against a constant pressure of 1 bar. the work done by the gas is equal to

Q. $5$ moles of ideal gas at temp. $T$ is compressed isothermally from $12$ atm to $24$ atm. Calculate the value of $10r$,

Q.

3 moles of ideal gas is heated as constant pressure from 27 degree cantegrate to 127 degree centigrade.

(a) Find the workdone for the expansion of gas?

(b) If the gas were expanded isothermally in a irreversible manner at 27 degree centigrade from 1 atmosphere to 0.7 atmosphere. Calculate the workdone.

Q. Calculate the work done when $5$ moles of oxygen gas contracts isothermally from $85L$ to $15L$ against a constant pressure of $2atm$ at ${25}^{0}C$.

1. $70Latm$
2. $14.0Latm$
3. $140Latm$
4. $7.0Latm$