**Branch :**First Year-Engineering Syllabus

**Subject :**Chemistry

## Reversible reactions

**Reversible reactions: **

All chemical reactions are reversible in principle, and for many the reverse reaction is readily observable in practice as well, and must be allowed for in the rate equation:

This differential equation is of exactly the same form as equation , and can be solved in the same way:

Therefore

Taking exponentials of both sides, we have

which can be rearranged to give

This is the value of p after infinite time, because the exponential term approaches zero as t becomes large. The expected behavior is illustrated in Figure 1.

Figure 1. First-order decay for a reversible reaction