Question

If pH of a solution decreases from 5 to 2, then it is

• A. diluted 1000 times
• B. concentrated 1000 times
• C. diluted 100 times
• D. concentrated 100 times

Answer 1

Answer: (B)

concentrated 1000 times

Answer 2

When $pH = 5, [H^{+}] = 10^{-5}$ When $pH=5, [H^{+}]=10^{-2}$ When the $pH$ decreases from $5$ to $2$ the solution is concetrated $10^{3 }(10^{-5} \times 10^{3} = 10^{-2})$ times i.e.. $1000$ times