PV Work

Q. An ideal gas is compressed to half its initial volume by means of several process. Which of the process results in maximum work done on the gas?

1. Adiabatic
2. isobaric
3. isothermal
4. Equal in all of above.

Q.

A gas expands by 0.5 litre against a constant pressure of one atmosphere. The work done is as follows.

1. -50.554

2. 45.2 J

3. -45.2 J

4. -50.664 J

Q. The area under a PV graph gives the work done.

1. True
2. False

Q. An ideal gas expands in volume from ${10}^{-3}$ to ${10}^{-2}{m}^3$ at 300 K against a constant pressure of ${10}^5$ Pa. Work done is

1. - 900 kJ
2. - 270 kJ
3. - 900 J
4. 900 kJ

Q. An ideal gas expands in volume from ${10}^{-3}{m}^3$ to ${10}^{-2}{m}^3$ at $300K$ against a constant pressure at ${10}^{5}N/m^2$. The work done is:

1. $900kJ$
2. $600kJ$
3. $-900J$
4. $270kJ$

Q. 8 g oxygen gas is expanded isothermally at ${27}^{c}ircC$ from 2 $d{m}^3$ to 8 $d{m}^3$at a constant external pressure of 4 atm. If the magnitude of work done in this process is used in lifting body of mass 40 kg, the height in (metre) upto which the body can be lifted is (g=10 $m{s}^{-2}$)

Q. One mole of Helium gas undergoes a reversible cyclic process ABCDA as shown in the figure.
Assuming gas to the ideal, answer the following questions:

What is the net work involved in the process A to C?

1. $300\text{R ln2 J}$
2. $-100R(1-\text{ln}8)$
3. $-100R(1+\text{ln}8)$
4. $200\text{J}$

Q.

An ideal gas expands in volume from $1\times {10}^{-3}$ to $1\times {10}^{-2}{m}^3$ at $300K$ against a constant pressure of $1\times {10}^{5}N{m}^{-2}$. The work done is

1. 270 kJ

2. −900 kJ

3. 900 kJ

4. −900 J

Q. An ideal gas is allowed to expand from $1L$ to $10L$ against a constant external pressure of $1$ bar. The magnitude of work done in $J$ is:

Q. An ideal gas expand in volume from $1\times {10}^{-3}{m}^{3}to1\times {10}^{-2}{m}^3$ at 300 K, against a constant pressure of $1\times {10}^{\alpha }{m}^{-2}$ the work done is:

1. -900 J
2. 900 kJ
3. 2780kJ
4. -900 kJ

Q. Calculate the work done (in Joules) when $0.2$ mole of an ideal gas at $300$K expands isothermally and reversibly from an initial volume of $2.5$ liters to the final volume of $25$ liters.

1. $996$
2. $-1148$
3. $11.48$
4. $897$

Q. Match the following : (Symbols have standard meaning)

Q. $2Al+3MnO\stackrel{\Delta }{\to }A{l}_2{O}_3+3Mn$
$108.0$ g of $Al$ and $213.0$ g of $MnO$ were heated to initiate the reaction. (Molecular weight of $MnO=71$ g/mol and atomic weight of $Al=13$ g)

1. $Al$ is present in excess.
2. $MnO$ is present is excess.
3. $54.0$ g of $Al$ is required.
4. $159.0$ g of $MnO$ is in excess.

Q.

1 g $H_2$ gas as STP is expanded so that volume is doubled. Hence, work done is

1. 22.4 L atm

2. 5.6 L atm

3. 111.2 L atm

4. 1.135 kJ

Q. One mole of Helium gas undergoes a reversible cyclic process ABCDA as shown in the figure.
Assuming gas to the ideal, answer the following questions:

What is the net work involved in the process A to C?

1. $-100R(1-\text{ln}8)$
2. $300\text{R ln2 J}$
3. $-100R(1+\text{ln}8)$
4. $200\text{J}$

Q. A gas expands from $6m^3$ to $8m^3$ in a container against a constant external pressure of 3 Pa. The work done by the gas is:

1. - 2 J
2. - 6 J
3. + 18 J
4. + 24 J

Q. The area under a PV graph gives the work done.

1. True
2. False

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

1. $25\text{J}$
2. $30\text{J}$
3. $-30\text{J}$
4. $5\text{kJ}$

Q. The heat solution of anhydrous $Cu{SO}_4$ is $-15.9kcal$ and that of $Cu{SO}_4.5H_{2}O$ is $2.8kcal$. Calculate the heat of hydration of $Cu{SO}_4$.

1. $-18.7kcal$
2. $+18.7kcal$
3. $-13.1kcal$
4. None of these

Q. A sample of ideal gas has an internal energy U and is then compressed to one-half of its original volume while the temperature stays the same. What is the new internal energy of the ideal gas in terms of U?

1. U
2. 1/2U
3. 1/4U
4. 2U

Q. Given below are two reversible reactions :
$A+B\rightleftharpoons Z$; $K_{c_1}=24$
$2B+C\rightleftharpoons 2Y$; $K_{c_2}=16$

Q.

1 g $H_2$ gas as STP is expanded so that volume is doubled. Hence, work done is

1. 22.4 L atm

2. 5.6 L atm

3. 111.2 L atm

4. 1.135 kJ

Q.

Temperature of 5 moles of a gas is decreased by 2K at constant pressure. Indicate the correct statement.

1. Work done by the gas = 5R

2. Work done by the gas = 10R

3. Work done over the gas = 10R

4. Work done = 0