Calculate the average reaction rate N2 + H2 = 2NH3, if the initial concentration of N2 was 0.90 mol / L

Calculate the average reaction rate N2 + H2 = 2NH3, if the initial concentration of N2 was 0.90 mol / L, and H2 was -1.10 mol / L. After 15 s, the concentration of N2 decreased to 0.83 mol / L. determine the average reaction rate and H2 concentration at this point in time.

N2 + 3H2 = 2NH3
Let’s find the average reaction rate for nitrogen:
ΔC (N2) = 0.9 – 0.83 = 0.07 mol / l;
v = ΔC (N2) / Δt = 0.07 / 15 = 0.00467 mol / (l * s);
If the nitrogen concentration has dropped by 0.07 mol / L, the hydrogen concentration should decrease three times more (according to the stoichiometry of the reaction):
C (H2) = 1.1 – 0.07 * 3 = 0.89 mol / l.
Answer: v = 0.00467 mol / (l * s); C (H2) = 0.89 mol / l.