What mass of ammonia (NH_3) is formed when 5.36 g of nitrogen gas (N_2) reacts with excess hydrogen gas according to the equation N_2 + 3H_2 → 2NH_3?

• A. 2.68 g
• B. 3.07 g
• C. 10.7 g
• D. 6.53 g

Answer: (D)

Verified step by step guidance

1. Write down the balanced chemical equation: \(\mathrm{N_2 + 3H_2 \rightarrow 2NH_3}\).
2. Calculate the molar mass of nitrogen gas (\(\mathrm{N_2}\)). Since each nitrogen atom has an atomic mass of approximately 14.0 g/mol, \(\mathrm{Molar\ mass\ of\ N_2 = 2 \times 14.0 = 28.0\ g/mol}\).
3. Convert the given mass of nitrogen gas to moles using the formula: \(\mathrm{moles = \frac{mass}{molar\ mass}}\). So, \(\mathrm{moles\ of\ N_2 = \frac{5.36\ g}{28.0\ g/mol}}\).
4. Use the stoichiometric ratio from the balanced equation to find moles of ammonia formed. According to the equation, 1 mole of \(\mathrm{N_2}\) produces 2 moles of \(\mathrm{NH_3}\). Therefore, \(\mathrm{moles\ of\ NH_3 = 2 \times moles\ of\ N_2}\).
5. Calculate the mass of ammonia formed by converting moles of \(\mathrm{NH_3}\) to grams. First, find the molar mass of ammonia: \(\mathrm{NH_3}\) has 1 nitrogen atom (14.0 g/mol) and 3 hydrogen atoms (3 x 1.0 g/mol), so \(\mathrm{Molar\ mass\ of\ NH_3 = 14.0 + 3 = 17.0\ g/mol}\). Then, use \(\mathrm{mass = moles \times molar\ mass}\) to find the mass of ammonia.