Answer
(a) $pOH = 6.08$
(b) $pOH = 12.74$
(c) $pOH = 5.59$
(d) $pOH = 1.274$
Work Step by Step
1. Calculate the pOH Value
$pH = -log[H_3O^+]$
$pH = -log( 1.2 \times 10^{- 8})$
$pH = 7.92$
$pOH + pH = 14$
$pOH = 14 - pH = 14 - 7.92$
$pOH = 6.08$
2. Calculate the pOH Value
$pH = -log[H_3O^+]$
$pH = -log( 0.055)$
$pH = 1.26$
$pOH + pH = 14$
$pOH = 14 - pH = 14 - 1.26$
$pOH = 12.74$
3. Calculate the pOH Value
$pH = -log[H_3O^+]$
$pH = -log( 3.9 \times 10^{- 9})$
$pH = 8.41$
$pOH + pH = 14$
$pOH = 14 - pH = 14 - 8.41$
$pOH = 5.59$
4. Calculate the pOH Value
$pH = -log[H_3O^+]$
$pH = -log( 1.88 \times 10^{- 13})$
$pH = 12.726$
$pOH + pH = 14$
$pOH = 14 - pH = 14 - 12.726$
$pOH = 1.274$
