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Multiple Choice
Nitrogen and hydrogen combine to form ammonia via the following reaction: 1 N2 (s) + 3 H2 (g) β 2 NH3 (g) What mass of nitrogen is required to completely react with 800.0 mL H2 at STP?
A
0.333 g
B
0.512 g
C
0.802 g
D
1.01 g
E
1.36 g
Verified step by step guidance
1
First, understand the stoichiometry of the reaction: 1 mole of N2 reacts with 3 moles of H2 to produce 2 moles of NH3. This means the molar ratio of N2 to H2 is 1:3.
Next, recall that at STP (Standard Temperature and Pressure), 1 mole of any gas occupies 22.4 liters. Convert the volume of H2 from milliliters to liters: 800.0 mL = 0.800 L.
Calculate the number of moles of H2 using the volume at STP: \( \text{moles of } H_2 = \frac{0.800 \text{ L}}{22.4 \text{ L/mol}} \).
Using the stoichiometric ratio from the balanced equation, determine the moles of N2 required: \( \text{moles of } N_2 = \frac{1}{3} \times \text{moles of } H_2 \).
Finally, calculate the mass of nitrogen needed using its molar mass (28.02 g/mol): \( \text{mass of } N_2 = \text{moles of } N_2 \times 28.02 \text{ g/mol} \).