Question

A ten fold increase in the $ [H^+] $ of a solution

• A. increases its $ pH $ by one unit
• B. decreases its $ pH $ by one unit
• C. increases its $ pH $ by $ 10 $ unit
• D. decreases its $ pH $ by $ 10 $ unt

Answer 1

Answer: (B)

$pH_1 = - log[H_1^+]$
$pH_2 = - log[10H_1^+]$
$ = - log [H^+] - log \,10$
$ = - log \,[H^+] - 1$
$ = pH_1 - 1$