Question

Ph larutan 500 mL Ca(OH)2 0,0005 M adalah....
a. 11
b. 9
c. 7
d.5
e.3
bantu jawab pakai caranya ya

Answer 1

Diket. volum larutan = 500 ml
         konsentrasi Ca(OH)'2' = [Ca(OH)2] = 0,0005 M = 5. 10^-4 M
ditanya pH larutan?
Jawab:
abaikan volum, karena isi larutan cuma Ca(OH)2
Ca(OH)2 --> Ca^2+  + 2  OH^-
[OH^-] = 2 [Ca(OH)2] = 2 . 5 . 10^-4 M = 10^-5 M
POH = - log (10^-5) = 5
pH = 14 - POH = 14 - 5 = 9
Jadi jawaban B