Answer
(a) $[HBr] = 0.758M$
(b) $[HBr] = 3.46 \times 10^{- 3}M$
(c) $[HBr] = 5.37 \times 10^{- 7}M$
Work Step by Step
- Since HBr is a strong acid: $[H_3O^+] = [HBr]$
Therefore, if we find $[H_3O^+]$, we get the HBr concentration.
(a)
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 0.12}$
$[H_3O^+] = 0.758M$
$[HBr] = 0.758M$
(b)
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 2.46}$
$[H_3O^+] = 3.46 \times 10^{- 3}$
$[HBr] = 3.46 \times 10^{- 3}$
(c)
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 6.27}$
$[H_3O^+] = 5.37 \times 10^{- 7}$
$[HBr] = 5.37 \times 10^{- 7}$
