Question

How many number of molecules and atoms respectively are present in $2.8$ litres of a diatomic gas at $STP$?

• A. $6.023\times10^{23}, 7.5\times10^{23}$
• B. $6.023\times10^{23}, 15\times10^{22}$
• C. $7.5\times10^{22}, 15\times10^{22}$
• D. $15\times10^{22}, 7.5\times10^{23}$

Answer 1

Answer: (C)

Number of molecules of gas at $STP$
$=\frac{6.023\times10^{23}\times2.8}{22.4} $
$= 7.5 \times10^{22} $ Molecules
Number of atoms in diatomic molecule
$ = 2 \times 7.5 \times10^{22} = 15 \times10^{22}$ atoms