Question

What volume of NO gas at STP can be produced from 7.0 moles of nitrogen dioxide (NO₂) according to the following equation? 3NO₂ + H₂O → 2HNO₃ + NO *

Answer 1

The balanced equation for considered reaction can be written as follows

$3NO_2 + H_2O \rightarrow 2HNO_3 + NO$

$\frac{\nu (NO_2)}{n(NO_2)} = \frac{V(NO)}{V_M \cdot n(NO)}$

where $\nu$ - amount, mol; $V$ - volume, L; $V_M$ - molar volume of a gas, $V_M=22.4 \; L/mol$ ; $n$ - number of molecules in the balanced equation.

$V(NO)=\frac{\nu (NO_2) \cdot V_M \cdot n(NO)}{n(NO_2)}$

$V(NO)=\frac{7.0 \cdot 22.4 \cdot 1}{3} \approx 52.3 \; L$

Answer: 52.3 L.