Answer
(a) pH = 0, pOH = 14: Acidic.
(b) pH = 3.77, pOH = 10.23: Acidic.
(c) pH = 7.167, pOH = 6.833: Basic.
(d) pH = 10.03, pOH = 3.97: Basic.
Work Step by Step
- If pH > pOH, the solution is basic, if pH < pOH, the solution is acidic:
(a)
$pH = -log[H_3O^+]$
$pH = -log( 1)$
$pH = 0$
$pOH + pH = 14$
$pOH = 14 - pH = 14 - 0$
$pOH = 14$
(b)
$pH = -log[H_3O^+]$
$pH = -log( 1.7 \times 10^{- 4})$
$pH = 3.77$
$pOH + pH = 14$
$pOH = 14 - pH = 14 - 3.77$
$pOH = 10.23$
(c)
$pH = -log[H_3O^+]$
$pH = -log( 6.8 \times 10^{- 8})$
$pH = 7.167$
$pOH + pH = 14$
$pOH = 14 - pH = 14 - 7.167$
$pOH = 6.833$
(d)
$pH = -log[H_3O^+]$
$pH = -log( 9.3 \times 10^{- 11})$
$pH = 10.03$
$pOH + pH = 14$
$pOH = 14 - pH = 14 - 10.03$
$pOH = 3.97$
