Question

A diatomic gas undergoes a process represented by $P{V}^{1.3}=constant$. Choose the incorrect statement.

• A. The gas expands by absorbing heat from the surroundings
• B. The gas cools down during expansion
• C. The work done by surroundings during expansion of the gas is negative
• D. None of these

Answer 1

Answer: (A)

The gas expands by absorbing heat from the surroundings

PV^γ=constant is the equation for Adiabatic process.

Here γ = 1.3

In an adiabatic system, there is no heat exchange from the surrounding.

(A) is incorrect as it says that gas expands by absorbing heat from surroundings which contradicts basic definition of adiabatic process.

(B) is correct as if the gas expands, it does so at the cost of its internal energy, if internal energy decreases, temperature also decreases.

(C) The work done by surroundings is negative since the expansion of gas is considered to be positive according to convention. so workdone by sytem on surroundings is positive and work done by surroundings on system is negative.

PVγ=constant
by surroundings