The difference between C ¯ p and C ¯ V is C ¯ p and C ¯ V signify molar quantities]

larger in case of gases in comparison to solids and liquids

larger in case of liquids in comparison to gases and solids

larger in case of solids in comparison to gases liquids

equal in solids, liquids and gases

MEDIUM

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A piston is cleverly designed so that it extracts the maximum amount of work out of a chemical reaction, by matching P_external to the P_internal at all times. This 8cm diameter piston initially holds back 1 mol of gas occupying 1 L, and comes to rest after being pushed out a further 2 L at 25^oC .After exactly half of the work has been done, the piston has travelled out a total of

50% studentsanswered this correctly

Important Questions on Chemical Thermodynamics

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

The quantity of heat (in $J$ ) required to raise the temperature of $1.0 k g$ of ethanol from $293.45 K$ to the boiling point and then change the liquid to vapor at that temperature is closest to [Given, boiling point of ethanol $351.45 K$ . Specific heat capacity of liquid ethanol $2.44 J g^{- 1} K^{- 1}$ . Latent heat of vaporisation of ethanol $855 J g^{- 1}$ ]

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

Two moles of helium gas is mixed with three moles of hydrogen molecules (taken to be rigid). What is the molar specific heat of mixture at constant volume?

(R = 8.3 J / m o l K)

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

At constant pressure, the heat of formation of a compound is not dependent on temperature, when

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

The difference between

{\bar{C}}_{p}

and

{\bar{C}}_{V}

[{\bar{C}}_{p}

and

{\bar{C}}_{V}

signify molar quantities]

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

A gas is allowed to expand in a well-insulated container against a constant external pressure of

2.5 atm

from an initial volume of

2.50 L

to a final volume of

4.50 L .

The change in internal energy

ΔU

of the gas in joules will be

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

A gas can expand from

100 mL

250 mL

under a constant pressure of

2 atm

. The work done by gas is

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

For one mole of an ideal gas, which of these statements must be true?
(a) Internal energy

(U)

and enthalpy

(H)

each depends on temperature.
(b) Compressibility factor

Z

is not equal to 1
(c)

C_{P, m} - C_{V, m} = R

(d)

dU = C_{v} dT

for any process

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

A piece of metal weighing

100 g

is heated to

80 ° C

and dropped into

1 kg

of cold water in an insulated container at

15 ° C

. If the final temperature of the water in the container is

15.69 ° C

, the specific heat of the metal in

J / g ° C

. is

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

At constant volume,

4 m o l

of an ideal gas when heated from

300 K

500 K

changes its internal energy by

5000 J .

The molar heat capacity at constant volume is ________

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

5

moles of an ideal gas at

100 K

are allowed to undergo reversible compression till its temperature becomes

200 K .

C_{V} = 28 J K^{- 1},

calculate

∆ U

and

∆ p V

for the process.

(R = 8.0 J K^{- 1} m o l^{- 1})

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

Calculation the maximum work done in expanding

16 g

of oxygen at

300 K

and occupying a volume of

5 {dm}^{3}

isothermally until volume becomes

25 {dm}^{3}

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

X g

of ice at

0^{o} C

is added to 340g of water at

20^{o} C

. The final temperature of the resultant mixture is

5^{o} C

. The value of

X

(in g) is closest to

[Heat of fusion of ice

= 333 J / g

; Specific heat of water

= 4.184 J / g . K

]

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

What will be the heat change at constant volume fo the reaction whose heat change at constant pressure is

- 560 kcal

27 ° C ?

The reaction is:

C_{8} H_{16} + 12 O_{2} \to 8 {CO}_{2} + 8 H_{2} O

(Given

R = 2 {calmol}^{- 1} K^{- 1})

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

A thermally insulated rigid container of

1 L

volume contains a diatomic ideal gas at room temperature. A small paddle installed inside the container is rotated from the outside, such that the pressure rises by

10^{5} Pa

. The change in internal energy is close to

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

$200 mL$ of $0.2 M HCl$ is mixed with $300 mL$ of $0.1 M NaOH .$ The molar heat of neutralization of this reaction is $- 57.1 kJ .$ The increase in temperature in ${}^{\circ}C$ of the system on mixing is $x \times 10^{- 2} .$ The value of $x$ is (Nearest integer)

[Given: Specific heat of water $= 4.18 J g^{- 1} K^{- 1}$

Density of water $= 1.00 g {cm}^{- 3}$ ]

(Assume no volume change on mixing)

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

The correct option for free expansion of an ideal gas under adiabatic condition is

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

Five moles of an ideal gas at

1

bar and

298 K

is expanded into vacuum to double the volume. The work done is :

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

An ideal gas is allowed to expand from

1 L

10 L

against a constant external pressure of

1

bar. The work done in

k J

is:

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

For the isothermal reversible expansion of an ideal gas

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Heat and Work

Calculate the work done during compression of

2

mol of an ideal gas from a volume of

1 m^{3}

10

{dm}^{3}

300 K

against a pressure of

100 kPa

Important Questions on Chemical Thermodynamics

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