Consider an ideal gas confined in a cylinder with a frictionless piston. The reversible

expansion of gas takes place in a finite number of infinitesimally small

intermediate steps. If the P

pressure of gas ‘P’ by ‘dP’. Then gas expands reversibly and piston moves

through a distance ‘dl’.

expansion of gas takes place in a finite number of infinitesimally small

intermediate steps. If the P

_{ext}is infinitesimally less than internalpressure of gas ‘P’ by ‘dP’. Then gas expands reversibly and piston moves

through a distance ‘dl’.

Since dP is so small, for all practical purposes.

P

_{ext.}– P_{gas}= P.One work done by gas in one infinitesimal step (dw) can be expressed as;

dw = P ´ dV. [ w = P ´ DV]

\dw = PdV.

If the gas expands from V

reversible expansion. The total amount of work done would be equal to

_{1}to V_{2 }during isothermalreversible expansion. The total amount of work done would be equal to

What if the number of moles is not constant..?

ReplyDeletethere will apear an n in the last expression only which shows that the moles are n in number

DeleteThis comment has been removed by the author.

ReplyDeleteWhat if no of moles remains same

ReplyDeleteremove the n from the last expression so the resultant answer will be the answer to you question

Deletewhat will be the enthalpy change

ReplyDeleteFor a substance of fixed composition, the enthalpy changes with change in temperature at constant pressure, can be calculated as.....

DeleteDelta H= Integral Sign(a+bT+bT^-2) and Limits of integrals are T1 to T2

what will be the enthalpy change

ReplyDeleteFor a substance of fixed composition, the enthalpy changes with change in temperature at constant pressure, can be calculated as.....

DeleteDelta H= Integral Sign(a+bT+bT^-2) and Limits of integrals are T1 to T2

When will be work done +ve ?

ReplyDeleteW is +ve when the work is done ON the system by the surroundings.

DeleteWhen to use -nRT ln v2/v1 and -2.303nRTlogv2/v1

ReplyDelete