Question

It takes 24.56 mL of a sodium hydroxide solution to precisely neutralize 2.023 g of potassium hydrogen phthalate (F.W. = 204.22g/mol). What is the concentration of the sodium hydroxide solution?

Answer 1

Answer:

0.4033 M is the concentration of the sodium hydroxide solution.

Explanation:

Mass of potassium hydrogen phthalate = 2.023 g

Molar mass of potassium hydrogen phthalate = 204.22 g/mol

Moles of potassium hydrogen phthalate :

= $\frac{2.023 g}{204.22 g/mol}=0.009906 mol$

$C_8H_5KO_4+NaOH\rightarrow C_8H_4KO_4Na+H_2O$

According to reaction, 1 mole of potassium hydrogen phthalate reacts with 1mole of NaOH. Then 0.009906 moles of potassium hydrogen phthalate  will recat with:

$\frac{1}{1}\times 0.009906 mol=0.009906 mol$ of NaOH

Moles of NaOH = 0.009906 mol

Volume of NaOH solution = 24.56 mL = 0.02456 L

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

$[NaOH]=\frac{0.009906 mol}{0.02456 L}=0.4033 M$

0.4033 M is the concentration of the sodium hydroxide solution.