Question

The weight of $350$ mL of a diatomic gas at $0^{o}C$ and $2$ atm pressure is 1 g. The weight in g of one atom at $NTP$ is:

• A. $2.64\times {10}^{-23}g$
• B. $2.64\times {10}^{-22}g$
• C. $5.7\times {10}^{-23}g$
• D. $0.82\times {10}^{-22}g$

Answer 1

The correct option is C $5.7\times {10}^{-23}g$

$M=\frac{WRT}{PV}=\frac{1\times 0.0821\times 293}{2\times 0.350}=34.36$ g/mol.
The weight in g of one atom at NTP is $\frac{M}{N_A}=\frac{34.36}{6.023\times {10}^{23}}=5.7\times {10}^{-23}$g.