Question

A NaOH solution is standardized using the monoprotic primary standard potassium hydrogen phthalate, KHP (204.22 g/mol.) If 0.6986 g of KHP requires 43.92 mL of NaOH, what is the NaOH concentration

Answer 1

0.07789 M is the sodium hydroxide concentration.

Step-by-step explanation:

Mass of potassium hydrogen phthalate = 0.6986 g

Molar mass of potassium hydrogen phthalate = 204.22 g/mol

Moles of potassium hydrogen phthalate =
`(0.6986 g)/(204.22 g/mol)=0.003421 mol`

`NaOH+KHP\rightarrow NaKP+H_2O`

According to reaction , 1 mole og KHp reactswith 1 mole of NaOH , then 0.003421 moles of KHp will react with :

`(1)/(1)* 0.003421 mol=0.003421 mol`

Moles of NaOH = 0.003421 mole

Volume of NaOH solution = 43.92 ml = 0.04392 L ( 1 mL = 0.001L)

`Concentration=(Moles)/(Volume(L))`

Concentration of NaOH :

`(0.003421 mol)/(0.04392 L)=0.07789 M`

0.07789 M is the sodium hydroxide concentration.