Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Concepts Of Physics MCQ Edition [Volume 2]
Exam
Concepts Of Physics MCQ Edition [Volume 2]
Subject
Physics
Chapter
Specific Heat Capacities of Gases

Concepts Of Physics MCQ Edition [Volume 2] · Physics · Specific Heat Capacities of Gases

To raise the temperature of 2 mole of an ideal gas from 30^ ^ ^ C...

To raise the temperature of 22 mole of an ideal gas from 30^{}^{{}^{\circ}} C to 35^{}^{{}^{\circ}} C at constant pressure, 7070 calories of heat is required. The amount of heat needed to raise the temperature of the same gas across the same range at constant volume is

Options

  1. A7070 calories
  2. B9090 calories
  3. C5050 calories
  4. D3030 calories

Correct answer

C. 5050 calories

Step-by-step solution

Given n=2n = 2, ΔT=35∘C−30∘C=5 K\Delta T = 35^{{}^{{}^{\circ}}}\text{C} - 30^{{}^{{}^{\circ}}}\text{C} = 5 \text{ K}, and Qp=70 calQ_p = 70 \text{ cal}.

The heat required at constant pressure is given by:

Qp=nCpΔTQ_p = n C_p \Delta T

70=2×Cp×570 = 2 \times C_p \times 5

Cp=7 cal mol−1\textK−1C_p = 7 \text{ cal mol}^{-1}\textK^{-1}

Using the relation Cp−Cv=RC_p - C_v = R and taking R≈2 cal mol−1\textK−1R \approx 2 \text{ cal mol}^{-1}\textK^{-1}:

Cv=7−2=5 cal mol−1\textK−1C_v = 7 - 2 = 5 \text{ cal mol}^{-1}\textK^{-1}

The heat required at constant volume is:

Qv=nCvΔTQ_v = n C_v \Delta T

Qv=2×5×5=50 calQ_v = 2 \times 5 \times 5 = 50 \text{ cal}
Practice Specific Heat Capacities of Gases on Quantrex Academy →

More from Specific Heat Capacities of Gases

The ratio of molar heat capacities for an ideal gas is given as C_p / C_V = 7/6 . Find… Concepts Of Physics MCQ Edition [Volume 2]An ideal gas has a molar heat capacity ratio of C_p / C_V = 7/6 . Determine the change in… Concepts Of Physics MCQ Edition [Volume 2]As illustrated in the figure, a cylindrical container holds oxygen ( γ = 1.4 ) and is… Concepts Of Physics MCQ Edition [Volume 2]A vessel containing one mole of a monatomic ideal gas (molecular weight = 20 g mol^ -1 )… Concepts Of Physics MCQ Edition [Volume 2]When 50 J of heat is supplied to an ideal gas, it expands from 100 cm^3 to 200 cm^3 at a… Concepts Of Physics MCQ Edition [Volume 2]An ideal gas expands from 100 cm^3 to 200 cm^3 at a constant pressure of 2.0 × 10^5 Pa… Concepts Of Physics MCQ Edition [Volume 2]An ideal gas expands from 100 cm^3 to 200 cm^3 at a constant pressure of 2.0 × 10^5 Pa… Concepts Of Physics MCQ Edition [Volume 2]During a particular process, a monatomic ideal gas absorbs an amount of heat Q and… Concepts Of Physics MCQ Edition [Volume 2] Full Specific Heat Capacities of Gases list All Concepts Of Physics MCQ Edition [Volume 2] PYQs