The proposed mechanism for a reaction is: Step 1: A + B X (fast) Step 2: X + C Y (slow) Step 3: Y D (fast) What is the overall reaction?

(slow) xy2+z→xy2z (fast) c step1:step2:xy2+z2→xy2z2

Explanation:

Step1: xy2+z2→xy2z2 (slow)

Step2: xy2z2→xy2z+z (fast)

2XY 2 + Z 2 → 2XY 2 Z

Rate = k[xy2][z2]

When the two elementary steps are summed up, the result is equivalent to the stoichiometric equation. Hence, this mechanism is acceptable. The order of both elementary steps is 2, which is '≤3'; this also makes this mechanism acceptable. Furthermore, the rate equation aligns with the experimentally determined rate equation, and this also makes this mechanism acceptable. Therefore, since all the three rules have been observed, this mechanism is possible.