Question

Many biochemical reactions are catalyzed by acids. A typical mechanism consistent with experimental result (in which HA is the acid and X is the reaction) is

stepl : Fast, reversible : HA + H+ + A-

$step 2: Fast, reversible: X + H^{+}\leftrightarrow XH^{+}$

$step 3: Slow: XH^{+}\rightarrow products$

What is the rate law that is consistent with the proposed mechanism?

Answer 1

Among all the three steps,

step3 is the slowest step, since the rate of the reaction depends on the slowest step, the rate law can be written as

r = k [XH⁺]