Question

An aqueous solution of potassium hydroxide is standardized by titration with a 0.122 M solution of hydrobromic acid. If 22.1 mL of base are required to neutralize 18.8 mL of the acid, what is the molarity of the potassium hydroxide solution?

Answer 1

The molarity of the potassium hydroxide solution is 0.104 M

Step-by-step explanation:

Step 1: Data given

Molarity of hydrobromic acid (HBr) = 0.122 M

Volume of potassium hydroxide (KOH) = 22.1 mL = 0.0221 L

Volume of hydrobromic acid = 18.8 mL = 0.0188 L

Step 2: The balanced equation

HBr(aq) + KOH(aq) → KBr(aq) + H2O(l)

Step 3: Calculate moles of HBr

Moles HBr = molarity HBr * volume HBr

Moles HBr = 0.122 M * 0.0188 L

Moles HBr = 0.0022936 moles

Step 4: Calculate molarity of KOH

We need 0.0022936 moles of KOH to neutralize the HBr

Molarity = moles / volume

Molarity KOH = 0.0022936 moles /0.0221 L

Molarity KOH = 0.104 M

The molarity of the potassium hydroxide solution is 0.104 M