\(2\; mole \;\mathrm{NH}_{3}(\mathrm{g})\) requires \(3\; mole \;\mathrm{H}_{2}(\mathrm{g})\)
\(20 \;mole\; \mathrm{NH}_{3}(\mathrm{g})\) requires
\(=\frac{3}{2} \times 20 \text { mole } \mathrm{H}_{2}(\mathrm{g})\)
\(=30\;mole\)