Helpp with thermodynamics and specific heat question

[TheTourist]

For an ideal monatomic gas, the molar specific heat at constant volume,
C_v=3/2R, where R is the gas constant. The heat capacity at constant volume of a gas is measured to be 43.58kJK^-1. How many kg-moles of the gas are present?




Iv tried looking in the lecture notes and in the textbook, but can't find anything of use.

Iv made an attempt and got 3.5kg-moles. Not sure that its right though. I used R=kN_A, where k is Boltzmann constant and N_A is Avogadros number.

 

[Andrew Mason]

For an ideal monatomic gas, the molar specific heat at constant volume,
C_v=3/2R, where R is the gas constant. The heat capacity at constant volume of a gas is measured to be 43.58kJK^-1. How many kg-moles of the gas are present?




Iv tried looking in the lecture notes and in the textbook, but can't find anything of use.

Iv made an attempt and got 3.5kg-moles. Not sure that its right though. I used R=kN_A, where k is Boltzmann constant and N_A is Avogadros number.

The heat capacity of n moles is n times the molar heat capacity.

The heat capacity of one mole of gas at constant volume is that amount heat flow required to raise the temperature one degree:

$$C_v = Q/\Delta T$$

If there are n moles, multiply both sides by n to determine the amount of heat flow per degree of temperature change.

AM