1. 100 ml Ba(OH)2 0,02 M 2. 100ml NH4OH 0,1 M (Kb: 10 pangkat -5) 3.100Ml LiOH 0,04M 4.50Ml AI(OH)3 0,04 M (Kb: 10 pangkat -6 5. 50Ml Sr (OH)2 0,005 M Pasangan

1.) Ba(OH)2 → ba^2+ + 2OH^-
OH- = 0,04 = 4×10^-2
pOH = -log [OH-]
-log4×10^-2
=2 -log4
2.) NH4OH ←→ NH4^+ + OH^-
[OH]= √kb × Mb
= √10^-5×1×10^-1
=√10^-6
=10^-3
pOH = -log [OH-]
= -log 1.10^-3
=3
3.) LiOH → Li^+ + OH^-
ph = -log 4.10^-2
= 2-log 4
4.) Al(OH)3 → Al^3+ + 3OH^-
[OH] = √kb. Mb
=√10^-6×4.10^-2
=2.10^-4
ph = -log 2.10^-4
=4-log2
5.) Sr(OH)2 ←→ Sr^2+ + 2OH^-
[OH] = 2×5.10^-3
= 10^-2
ph = -log 10^-2
= 2

pasangan larutan yang memiliki ph sama yaitu nomor 1&3 (catatan : tanda(^) = dibaca pangkat) :))))