In: Chemistry
Determine the pH of a KOH solution made by mixing 0.251 g KOH with enough water to make 1.00
Molar mass of KOH = 56 gm
mass of KOH = 0.251 g
Number of moles of KOH = mass/molar mass
= 0.251/56
=4.482*10^-3 mol
Volume = 1*10^2 mL =0.1 L
Molarity of KOH = number of moles/ Volume
= (4.482*10^-3)/0.1
=0.04482 M
KOH-->K+ +OH-
[OH-] = [KOH]= 0.04482 M
pOH = - log[OH-]
= -log (0.04482)
= 1.35
pH= 14- pOH
= 14- 1.35
= 12.65
Answer: e