Question

Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory as a primary standard. It has the unwieldy formula of KHC8H4O4. This is often written in shorthand notation as KHP. If 31.0 mL of a barium hydroxide solution are needed to neutralize 1.37 grams of KHP, what is the molarity of the barium hydroxide solution

Answer 1

0.1082M of Barium Hydroxide

Step-by-step explanation:

KHP reacts with Ba(OH)2 as follows:

2KHP + Ba(OH)2 → 2H2O + Ba²⁺ + 2K⁺ + 2P²⁻

Where 2 moles of KHP reacts per mole of barium hydroxide

To solve this question we must find the moles of KHP in 1.37g. With these moles and the reaction we can find the moles of Ba(OH)2 and its molarity using the volume of the solution (31.0mL = 0.0310L) as follows:

Moles KHP -Molar mass: 204.22g/mol-

1.37g * (1mol / 204.22g) = 0.006708 moles KHP

Moles Ba(OH)2:

0.006708 moles KHP * (1mol Ba(OH)2 / 2mol KHP) =

0.003354 moles Ba(OH)2

Molarity:

0.003354 moles Ba(OH)2 / 0.0310L =

0.1082M of Barium Hydroxide