Question

If $224ml$ of triatomic gas has a mass of $1g$ at $273K$ and $1atm$ pressure, then the mass of one atom is-

• A. $8.30\times {10}^{-23}gm$
• B. $2.08\times {10}^{-23}gm$
• C. $5.53\times {10}^{-23}gm$
• D. $6.24\times {10}^{-23}gm$

Answer 1

The correct option is C $5.53\times {10}^{-23}gm$

$1$ mole gas occupies $22.4$ litres $=22,400$ ml at STP condition.

$224$ ml will then be occupied by $0.01$ mol

The weight of 0.01 mol $=1$ g

1 mole of the given gas weighs $=100$ g

$6.023\times {10}^{23}\times 3$ (since its trimolecular) atoms has weight of 100 g.

Mass of one atom $=\frac{100g}{6.023\times {10}^{23}\times 3}$

$=0.0553\times 100g=5.53\times {10}^{-23}g$

Hence, option C is correct.