Answer:
10.6
Step-by-step explanation:
We'll begin by calculating the pOH of the solution. This can be obtained as follow:
Concentration of Hydroxide ion [OH¯] = 0.0004 M
pOH =?
pOH = –Log [OH¯]
pOH = –Log 0.0004
pOH = 3.4
Finally, we shall determine the pH of the solution. This can be obtained as follow:
pOH = 3.4
pH =?
pH + pOH = 14
pH + 3.4 = 14
Collect like terms
pH = 14 – 3.4
pH = 10.6
Thus, the pH of the solution is 10.6