51.

Reaction(s) that are second order:

1. 2A -> B
2. B -> A + C
3. A + B -> C
4. B -> 2A

One or more answers are correct. Click on:

• a. if 1, 2, and 3 are correct
• b. if 1 and 3 are correct
• c. if 2 and 4 are correct
• d. if only 4 is correct
• e. if all are correct