The molar specific heat depends upon the type of gas. For monatomic gases it is 3/2 R or 2.98 Calories/mole*C. For diatomic gases (like O2 and N2) it is 4.97 Cal/mole*C. For polyatomic gaqses (like CO2) it is higher still.
You need to know what the gas is. Whoever assigned the problem should know that.
I assume that your number
22*10^22 is the number of molecules of gas. Divide that by Avogadro's number for the number of moles. It is about 1.38 moles.
Divide the Number of Calories removed by (molar specific heat)*(# of moles)
That will give you the temperature change. In this case it will be negative.
An ideal gas at 20 C consists of atoms 22*10^22. 4.5 J of thermal energy are removed from the gas. What is the new temperature in C?
2 answers
-272.97