MCQ
The heat energy required to raise the temperature of $5\,moles$ of an ideal gas to $5\,K$ at constant pressure is $600\,J$ . How much heat (in $J$ ) is required to raise the same mass of the same gas to $5\,K$ at constant volume ? (Take $R = 8.3\,J/mole-^oK$ )
  • A
    $207.75$
  • B
    $415.50$
  • $392.25$
  • D
    $784.50$

Answer

Correct option: C.
$392.25$
c
At constant pressure, heat energy required is given by

$\mathrm{Q}_{\mathrm{p}}=\mu \mathrm{C}_{\mathrm{p}} \Delta \mathrm{T}=600 \mathrm{J}(\text { given })$

where $\mu$ is the number of moles of ideal gas. At constant volume,

$\mathrm{Q}_{\mathrm{v}}=\mu \mathrm{C}_{\mathrm{v}} \mathrm{dT}=\mu\left(\mathrm{C}_{\mathrm{p}}-\mathrm{R}\right) \Delta \mathrm{T}$

$\left(\because C_{p}-C_{v}=R\right)$

$=600-\mu R . \Delta T$

$=600-5 \times 8.31 \times 5$

$=600-207.75=392.25 \mathrm{J}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A Carnot engine with efficiency $50\,\%$ takes heat from a source at $600\,K$. In order to increase the efficiency to $70\,\%$, keeping the temperature of sink same, the new temperature of the source will be $.........\,K$
The absolute temperature of a gas is determined by
Which one of the following statements does not hold good when two balls of masses $m _1$ and $m _2$ undergo elastic collision
The maximum vertical distance through which a fully dressed astronaut can jump on the earth is $0.5\, m$. If mean density of the moon is two-thirds that of the earth and radius is one quarter that of the earth, the maximum vertical distance through which he can jump on the moon and the ratio of time of duration of jump on the moon to that on the earth are
A spring of unstretched length $l$ has a mass $m$ with one end fixed to a rigid support .Assuming spring to be made of a uniform wire, the kinetic energy possessed by it if its free end is pulled with uniform velocity $v$ is
A block of mass $2\,kg$ hangs from the rim of a wheel of radius $0.5\,m$. On releasing from rest the block falls through $5\,m$ height in $2\,s$. The moment of inertia of the wheel will be ...... $kg - {m^2}$
The efficiency of a frictionless engine can be 100% only when the heat sink is:
One end of a string of length $L$ is tied to the ceiling of a lift accelerating upwards with an acceleration $2g$. The other end of the string is free. The linear mass density of the string varies linearly from $0$ to $\lambda$ from bottom to top.
When a train stops suddenly, passengers in the running train feel an instant jerk in the forward direction because
A diatomic gas molecule has translational, rotational and vibrational degrees of freedom. The ${C_P}/{C_V}$ is