Question

ammonia gas decomposes according to the equation:
$2nh_3(g) \
ightarrow n_2(g) + 3h_2(g)$
if 15.0 l of nitrogen is formed at stp, how many liters of hydrogen will be produced (also measured at stp)?
\bigcirc 90.0 l
\bigcirc 15.0 l
\bigcirc 45.0 l
\bigcirc 30.0 l
\bigcirc not enough information

Explanation:

Step1: Analyze the reaction stoichiometry

From the balanced equation \(2\text{NH}_3(\text{g})
ightarrow \text{N}_2(\text{g}) + 3\text{H}_2(\text{g})\), the mole ratio (and at STP, volume ratio) of \(\text{N}_2\) to \(\text{H}_2\) is \(1:3\).

Step2: Calculate volume of \(\text{H}_2\)

Given volume of \(\text{N}_2\) is \(15.0\) L. Let volume of \(\text{H}_2\) be \(V\). Using the volume ratio: \(\frac{V_{\text{H}_2}}{V_{\text{N}_2}}=\frac{3}{1}\). So \(V_{\text{H}_2}=3\times V_{\text{N}_2}=3\times15.0\) L \( = 45.0\) L.

Answer:

45.0 L (corresponding to the option with 45.0 L)