Question

Fritz Haber, a German chemist, discovered a way to synthesize ammonia gas (NH3) by combining hydrogen and nitrogen gases according to the following equation:

3H2(g) + N2(g) → 2NH3(g)

What volume of nitrogen is needed to produce 250.0 L of ammonia gas at STP?
L

What volume of hydrogen is needed to produce 2.50 mol NH3 at STP?
L

Answer 1

To produce 250.0 L of ammonia gas at STP, 22.4 L of nitrogen is needed. To produce 2.50 mol of ammonia gas at STP, 168 L of hydrogen is needed.

Step-by-step explanation:

The balanced chemical equation for the synthesis of ammonia gas is:

3H2(g) + N2(g) → 2NH3(g)

To find the volume of nitrogen needed to produce 250.0 L of ammonia gas at STP, we can use the stoichiometry of the balanced equation. The ratio of nitrogen to ammonia gas is 1:2, so if we need 2 moles of ammonia gas, we will need 1 mole of nitrogen gas. At STP, 1 mole of gas occupies 22.4 L. Therefore, the volume of nitrogen needed would be 22.4 L.

To find the volume of hydrogen needed to produce 2.50 mol of ammonia gas at STP, we once again use the stoichiometry of the balanced equation. The ratio of hydrogen to ammonia is 3:2, so for every 2 moles of ammonia gas, we need 3 moles of hydrogen gas. Using the molar volume at STP, we know that 1 mole of gas occupies 22.4 L. Therefore, the volume of hydrogen needed would be 3 × 2.50 × 22.4 = 168 L.

Answer 2

1) Write the balanced equation to state the molar ratios:

3H2(g) + N2(g) → 2NH3(g)

=> molar ratios = 3 mol H2 : 1 mol N2 : 2 mol NH3

What volume of nitrogen is needed to produce 250.0 L of ammonia gas at STP?

First, convert the 250.0 L of NH3 to number of moles at STP .

Use the fact that 1 mole of gas at STP occupies 22.4 L

=> 250.0 L * 1mol/22.4 L = 11.16 L

Second, use the molar ratio to find the number of moles of N2 that produces 11.16 L of NH3

=> 11.16 L NH3 * [1 mol N2 / 2 mol NH3] = 5.58 mol N2

Third, convert 5.58 mol N2 into liters at STP

=> 5.58 mol N2 * [22.4 L/mol] = 124.99 liters

Answer: 124,99 liters

What volume of hydrogen is needed to produce 2.50 mol NH3 at STP?


First, find the number of moles of H2 that produce 2.50 mol by using the molar ratios:

2.50 mol NH3 * [3mol H2 / 2 mol NH3] = 3.75 mol H2

Second, convert the number of moles to liters of gas at STP:

3.75 mol * 22.4 L/mol = 84 liters of H2

Answer: 84 liters