8.31

[Rachel Brown 3A]

On 8.31, the solution states that the molar heat capacity of a monatomic ideal gas at constant pressure is = 5/2 R and later states that the molar heat capacity of a monatomic ideal gas at constant volume is = 3/2 R. What does this mean and how can you find it?

[Jason Muljadi 2C]

The general equation that you're going to use is nC(delta)T or mC(delta)T. Now, C can either be C_p, which is constant pressure or C_v, which is constant volume. When you have C_p, you would use 5/2 R. When you have C_v, you would use 3/2 R. The R will be the gas constant, so you have to look at the units to find out which gas constant to use.

[Ya Gao]

It means that when a gas is working as an ideal gas, its Cv and Cp will be 3/2R and 5/2R. It can be found on the equation sheet.

[Kevin Ru 1D]

Just to add on that R represents the gas constant which varies depending on what units you are using. As mentioned above, it can be found on the constant and equations sheet on Dr. Lavelle's website.