EASY

Earn 100

A process in which the amount of heat supplied to the system goes fully to change its internal energy and temperature is

50% studentsanswered this correctly

Important Questions on Thermodynamics

MEDIUM

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

Five moles of an ideal gas at

293 K

is expanded isothermally from an initial pressure of

2.1 MPa

1.3 MPa

against at constant external pressure

4.3 MPa

. The heat transferred in this process is ___

{kJmol}^{- 1}

. (Rounded-off to the nearest integer)

[ Use $R = 8.314 J {mol}^{- 1} K^{- 1}$ ]

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

How much heat will be absorbed by $1$ mole of an ideal gas, if it is expanded reversibly from $5 L$ to $25 L$ at $27^{o} C$ ?

$(\log 3 = 0.5, \log 4 = 0.6, \log 5 = 0.7)$

MEDIUM

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

An ideal gas initially at temperature, pressure and volume,

27 ° C, 1.00

bar and

10 L

respectively is heated at constant volume until pressure is

10.0

bar, it then undergoes a reversible isothermal expansion until pressure is

1.00 bar,

what is the total work

W

, during this process?

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

One mole of an ideal gas at $27 ° C$ is taken from $A$ to $B$ as shown in the given $P V$ indicator diagram. The work done by the system will be _______ $\times 10^{- 1} J .$ [Given, $R = 8.3 J {mole}^{- 1} K, \ln 2 = 0.6931$ ] (Round off to the nearest integer)

(Round off to the nearest integer)

Question Image

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

100 mole

H_{2} O_{2}

decompose at

1 bar

and

300 K

, the work is done (

kJ

) by one mole of

O_{2} (g)

as it expands against

1 bar

pressure is:

2 H_{2} O_{2} (l) ⇌ 2 H_{2} O (l) + O_{2} (g)

(R = 8 .3 J K^{- 1} {mol}^{- 1})

HARD

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

At $25 ° C, 50 g$ of iron reacts with $HCl$ to form ${FeCl}_{2}$ . The evolved hydrogen gas expands against a constant pressure of $1 bar$ . The work done by the gas during this expansion is -_______ $J$ .

(Round off to the Nearest Integer)

[Given : $R = 8.314 J {mol}^{- 1} K^{- 1}$ . Assume, hydrogen is an ideal gas]

[Atomic mass off Fe is $55.85 u$ ]

HARD

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

During the free expansion of an ideal gas in an isolated chamber,

HARD

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

Write the conditions for maximum work done by the system.

MEDIUM

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

The magnitude of work done by a gas that undergoes a reversible expansion along the path $A B C$ shown in the figure is _________.
Question Image

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

Under the isothermal condition, 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 $= 100 J$ )

MEDIUM

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

For water at

100 ° C

and

1

bar,

Δ_{v a p} H - Δ_{v a p} U = \underline{} \times 10^{2} J {mol}^{- 1}

(Round off to the Nearest Integer)
[Use :

R = 8.31 J {mol}^{- 1} K^{- 1}]

[Assume volume of

H_{2} O (l)

is much smaller than volume of

H_{2} O (g)

. Assume

H_{2} O (g)

treated as an ideal gas]

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

An ideal gas undergoes isothermal expansion at constant pressure. During the process:

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

When an ideal gas expands isothermally from

5 m^{3}

10 m^{3}

25 ° C

against a constant pressure of

10^{7} N \cdot m^{- 2}

, then the work done on the gas is

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

Three mole of an ideal gas expand isothermally and reversibly from

10 m^{3}

20 m^{3}

300 K,

calculate the work done?

(R = 8.314 J K^{- 1} {mol}^{- 1})

HARD

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

One mole of an ideal gas at

900 K

, undergoes two reversible processes,

I

followed by

II

, as shown below. If the work done by the gas in the two processes are same, the value of

\ln \frac{V_{3}}{V_{2}}

Question Image

( $U$ : internal energy, $S :$ entropy, $p :$ pressure, $V :$ volume, $R$ : gas constant)

(Given: molar heat capacity at constant volume, $C_{V, m}$ of the gas is $\frac{5}{2} R$ )

Give your answer as the nearest integer.

HARD

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

The work done when

2

moles of an ideal gas expands reversibly and isothermally from a volume of

1 L

10 L

300 K

(R = 0.0083 kJ K {mol}^{- 1})

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

Two identical samples of gas are allowed to expand $(i)$ isothermally and $(ii)$ adiabatically. The amount of work done id then

EASY

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

The work done in

ergs

for the reversible expansion of one

mole

of an ideal gas from a volume of

10 litres

20 litres

25 ° C

MEDIUM

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

The three processes in a thermodynamic cycle shown in the figure are : Process $1 \to 2$ is isothermal; Process $2 \to 3$ is isochoric (volume remains constant); Process $1 \to 3$ is adiabatic.

Question Image

The total work done by the ideal gas in this cycle is, $10 J .$ The internal energy decreases by, $20 J$ in the isochoric process. The work done by the gas in the adiabatic process is, $- 20 J$ . The heat added to the system in the isothermal process is

HARD

Physics>Heat and Thermodynamics>Thermodynamics>Thermodynamic Processes and Indicator Diagrams

An ideal gas undergoes isothermal compression from

5 m^{3}

1 m^{3}

against a constant external pressure of

4 N m^{- 2}

. The heat released in this process is

24 J {mol}^{- 1} K^{- 1}

and is used to increase the pressure of

1

mole of

Al

. The temperature of

Al

increases by:

A process in which the amount of heat supplied to the system goes fully to change its internal energy and temperature is

Important Questions on Thermodynamics

Learn and Prepare for any exam you want !