Question

in a standardization of an unknown sodium hydroxide solution, 0.256g of KHP reacts with exactly 22.62 mL of the unknown sodium hydroxide solution. What is the molarity of the unknown solution

Answer 1

Answer: Molarity of NaOH solution is 0.0553 M.

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of KHP = 0.256 g

Molar mass of KHP = 204.22 g/mol

Putting values in above equation, we get:

$\text{Moles of KHP}=\frac{0.256g}{204.22g/mol}=0.00125mol$

The chemical reaction follows the equation:

$KHC_8H_4O_4(aq.)+NaOH\rightarrow Na_2C_8H_4O_4(aq.)+H_2O(l)$

By Stoichiometry of the reaction:

1 mole of KHP reacts with 1 mole of NaOH.

So, 0.00125 moles of KHP will react with = $\frac{1}{1}\times 0.00125=0.00125$ moles of NaOH.

To calculate the molarity of NaOH, we use the equation:

We are given:

Moles of NaOH = 0.00125 moles

Volume of solution = 22.62 mL

Putting values in above equation, we get:

$\text{Molarity of NaOH }=\frac{0.00125mol\times 1000}{22.62ml}=0.0553M$

Hence, the molarity of NaOH solution is 0.0553 M.