Question

The specific heat at constant volume for the monatomic argon is $0.075kcal/kgK$, whereas its gram molecular specific heat is $C_v=2.98cal/molK$. The mass of the argon atom is (Avogadro's number$=6.02\times {10}^{23}molecules/mol$)

• A. $6.60\times {10}^{-23}g$
• B. $3.30\times {10}^{-23}g$
• C. $2.20\times {10}^{-23}g$
• D. $13.20\times {10}^{-23}g$

Answer 1

Answer: (A)

$6.60\times {10}^{-23}g$

We substitute the value of 1 mole of molecules i.e.
1 mole = $6.02\times {10}^{23}molecules$
And now divide the values of the 2 specific heats to yield the mass of 1 molecule of Argon as
$\frac{2.98}{6.02\times {10}^{23}\times 0.075}$

$=6.6\times {10}^{-23}g$