A question about ideal gases?

Question

A mole of an ideal gas with Cp,m = 29 J mol^-1 k^-1 and Cv,m = 21 J mol^-1 k^-1 is heated from 40 to 80 degrees C while kept at a constant pressure. Calculate the heat Q supplied to the sample during the process. Calculate also the internal energy ΔU.

a) Q = 840 J ; ΔU = 840 J

a) Q = 840 J ; ΔU = 1160 J

a) Q = 1160 J ; ΔU = 840 J

a) Q = 1160 J ; ΔU = 1160 J

a) There is not enough information to determine Q and ΔU

Answer 1

I would go for there is not enough data to answer the question, but that maybe because im not to sure that u meant by cp,m and cv,m..

the ideal gas equation is:  pressure X volume=n (moles) X R (gas constant 8.31) Temperature (in kelvin, o'C= 273K)

and to work out Q the equation used is: Q= mass X c (specific heat capactity, 4.18 for water) X change in temperature

so with these equations, you may be able to work out the answer...

hope i helped...