Question

1. Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory to standardize strong base solutions. It has the unwieldy formula of KHC₈H₄O₄. This is often written in shorthand notation as KHP.

How many grams of KHP are needed to exactly neutralize 23.2 mL of a 0.557 M potassium hydroxide solution ?

2. Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory to standardize strong base solutions. It has the unwieldy formula of KHC₈H₄O₄. This is often written in shorthand notation as KHP.

What volume of a 0.458 M potassium hydroxide solution is needed to exactly neutralize 2.67 grams of KHP ?

3. A student is asked to standardize a solution of barium hydroxide. He weighs out 1.04 g potassium hydrogen phthalate (KHC₈H₄O₄, treat this as a monoprotic acid).

It requires 37.9 mL of barium hydroxide to reach the endpoint.

A. What is the molarity of the barium hydroxide solution?

This barium hydroxide solution is then used to titrate an unknown solution of hydrobromic acid.

B. If 21.7 mL of the barium hydroxide solution is required to neutralize 13.0 mL of hydrobromic acid, what is the molarity of the hydrobromic acid solution?

4. A student is asked to standardize a solution of calcium hydroxide. He weighs out 1.04 g potassium hydrogen phthalate (KHC₈H₄O₄, treat this as a monoprotic acid).

It requires 32.9 mL of calcium hydroxide to reach the endpoint.

A. What is the molarity of the calcium hydroxide solution?  M

This calcium hydroxide solution is then used to titrate an unknown solution of hydroiodic acid.

B. If 16.2 mL of the calcium hydroxide solution is required to neutralize 20.4 mL of hydroiodic acid, what is the molarity of the hydroiodic acid solution?  M

Answer 1

Question 1

How many grams of KHP are needed to exactly neutralize 23.2 mL of a 0.557 M potassium hydroxide solution

Concentraion of KOH = 23.2 x 0.557 / 1000 = 0.0129224 Moles

Hence the same moles of KHP need to  neutralize

0.0129224 Moles of KHP =   0.0129224 x 204.22= 2.639 gm

2.639 gm of KHP Is need.

Question 2

What volume of a 0.458 M potassium hydroxide solution is needed to exactly neutralize 2.67 grams of KHP  2.67 grams of KHP = 2.67 /204.22 = 0.013074 Moles

Volume of KOH need to  neutralize = 0.013074 x 1000 / 0.458 = 28.55 ml

Hence 28.55 ml of KHP is need.

Question 3

A student is asked to standardize a solution of barium hydroxide. He weighs out 1.04 g potassium hydrogen phthalate (KHC8H4O4, treat this as a monoprotic acid)

1.04 g potassium hydrogen phthalate = 1.04 /204. 22 = 0.005098 Moles .

molarity of the barium hydroxide =   0.005098 x 1000 / 37.9 = 0.1345 Moles