Two moles of an ideal gas expand spontaneously into vacuum. The work done is

Question

Two moles of an ideal gas expand spontaneously into vacuum. The work done is (A) 2J (B) 4J (C) zero (D) infinity

Tardigrade Admin · Accepted Answer

External pressure (pext)=0 (for vacuum) In other words, the gas expands against a zero external pressure. Hence, no work is done, because there is no force which oppose expansion. W=pextΔ V=0

Q. Two moles of an ideal gas expand spontaneously into vacuum. The work done is

2J

4J

zero

infinity

External pressure $(p_{e x t}) = 0$ (for vacuum) In other words, the gas expands against a zero external pressure. Hence, no work is done, because there is no force which oppose expansion. $W = p_{e x t} Δ V = 0$

Q. Two moles of an ideal gas expand spontaneously into vacuum. The work done is

2J

4J

zero

infinity

External pressure (pext​)=0 (for vacuum) In other words, the gas expands against a zero external pressure. Hence, no work is done, because there is no force which oppose expansion. W=pext​ΔV=0

External pressure $(p_{e x t}) = 0$ (for vacuum) In other words, the gas expands against a zero external pressure. Hence, no work is done, because there is no force which oppose expansion. $W = p_{e x t} Δ V = 0$