Question

What is the concentration of a NaOH solution that takes 23.7 mL to neutralize 20.0 mL of 0.500M HCl solution?

Answer 1

0.422 M NaOH solution.

Step-by-step explanation

Given:

Volume of NaOH solution, Vb = 23.7 mL

Volume of HCl solution, Va = 20.0 mL

Concentration of HCl solution, Ca = 0.500 M

What to find:

The concentration of NaOH solution.

Step-by-step solution:

Step 1: Write a balanced equation for the reaction to determine the mole ratio.

Equation: HCl + NaOH -----> NaCl + H₂O

Mole ratio: 1 1

Step 2: Calculate the concentration of NaOH solution.

The concentration of NaOH solution can be calculated using the formula below.

`\begin{gathered} (C_aV_a)/(n_a)=(C_bV_b)/(n_b) \\ \\ \Rightarrow C_b=(C_a* V_a* n_b)/(V_b* n_a) \end{gathered}`

Putting the values of the given parameters into the formula, we have;

`C_b=(0.500M*20.0mL*1)/(23.7mL*1)=(10M)/(23.7)=0.422\text{ }M`

Therefore, the concentration of NaOH solution to neutralize 20.0 mL f 0.500 M HCl solution is 0.422 M