The specific heat at constant volume 0 of one mole of an ideal monatomic gas is (ratios of R)

I've checked all my notes and my textbooks and I can't find any references to this:

A) 1/2R
B) R
C) 3/2R
D) 2R
E) 5/2R

Any help would be really appreciated, thanks =)

~ Also, the next question asks about the specific heat at a constant pressure (same multichoice answers). Are the two related?

General formula:

cv = R/(k - 1)
cp = k*R/(k - 1)

where k is the adiabatic index.


For monatomic gasses, k=5/3
For diatomic gasses, k=1.4
For more complicated molecules, k is much less.

As an engineer, k=1.4 is worth memorizing, because most of the time you deal with air. If you deal with noble gasses, you might memorize k=5/3 as well.

Crunching the algebra, and you get for a monatomic gas:
cv = 3*R/2
cp = 5*R/2

The answer is 3/2 R or C since it's monatomic. If it was diatomic it would be 5/2. I take it you are dealing with isotherm's, adiabats, isochors, and isobars by chance?

The next question I'm not entirely sure but I think it is the same answer as the first one, C. Considering it is monatomic. Probably just a trick question.