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 34.10 mL of a barium hydroxide solution are needed to neutralize 2.050 grams of KHP, what is the concentration (mol/L) of the barium hydroxide solution

Answer 1

Answer:

0.1472 mol/L is the concentration of the barium hydroxide solution.

Explanation:

$2KHC_8H_4O_4+Ba(OH)_2\rightarrow Ba(KC_8H_4O_4)_2+2H_2O$

Mass of potassium hydrogen phthalate = 2.050 g

Molar mass of potassium hydrogen phthalate = $\frac{2.050 g}{204.2 g/mol}=0.01004 mol$

According to reaction , 2 moles of potassium hydrogen phthalate reacts with 1 mole of barium hydroxide, then 0.01004 moles of potassium hydrogen phthalate will :

$\frac{1}{2}\times 0.01004 mol=0.005020 mol$ of barium hydroxide

Moles of barium hydroxide = 0.005020 mol

Volume of the barium hydroxide solution = 34.10 mL = 0.03410 L

1 mL = 0.001 L

$Molarity=\frac{Moles}{Volume(L)}$

Molarity of the barium hydroxiude silution :

$=\frac{0.005020 mol}{0.03410 L}=0.1472 mol/L$

0.1472 mol/L is the concentration of the barium hydroxide solution.