During a constant pressure expansion, the sign of the temperature change

Question

is positive

is negative

is irrelevant because the temperature stays constant

depends on other factors

those are the choices given, please help me! thank you.

Answer 1

Let The ideal gas equation be

PV= RT

P = Pressure , V = volume

R gas constant , T= temperature in degree K ( Taking 1 mole of gas)

differentiating

P dV = V dP + R dT

If pressure is constant

dP = 0

PdV = RdT

If dV= +ve (for Expansion )

dT will also be positive

Hence Temperature will increase

thus temperature change is positive