Answer: The correct answer is 'increases to 100 times the original concentration'.
Step-by-step explanation:
let the initial pH be x
The original concentration of
initially present be y
...(1)
Final concentration of
when pH reduced by 2 be z
...(2)
Putting the value of 'x' from (1) into (2) we get :
![-log[y]-2=-log[z]](https://img.qammunity.org/2017/formulas/chemistry/high-school/hpsdf4mbpf2mjs2hth10k7qbmbg1jips5r.png)

When pH of a solution decreases by 2.0, hydronium ion concentration of the solution increases to 100 times the original concentration