A product (First order reaction). Three sets of experiment were performed for a reaction under similar experimental conditions: Run 1 100 ~mL of 10 M solution of reactant A Run 2 200 ~mL of 10 M solution of reactant A Run 3 100 ~mL of 10 M solution of reactant A +100 ~mL of H _ 2 O added. The correct variation of rate of reaction is
C. Run 3< Run 1 = Run 2
For a first-order reaction, rate = k[A], where rate is directly proportional to reactant concentration. Run 1: 100 mL of 10 M solution Concentration = 10 M Rate: r_1 = k 10 Run 2: 200 mL of 10 M solution Concentration remains 10 M (increasing volume doesn't change concentration) Rate: r_2 = k 10 Therefore r_1 = r_2 Run 3: 100 mL of 10 M solution + 100 mL of H₂O Total moles of A = 10 M × 0.1 L = 1 mol Total volume = 0.2 L New concentration = 1 mol / 0.2 L = 5 M Rate: r_3 = k 5 Therefore r_3 < r_1 = r_2
Related: Chemistry — Chemical Kinetics · All PYQ Banks