Question

What is the volume of a 0.5 mol/l naoh solution required to completely react with 20 ml of a 2.0 mol/l hcl solution?

Answer 1

The chemical reaction that occurs between
`NaOH` and
`HCl` is:

`NaOH + HCl \rightarrow NaCl+H_2O`

Using formula:

`M_1V_1 = M_2V_2`

where M is the concentration in molarity and V is volume of the solution.

Molarity of
`NaOH = 0.5 mol/L` (given)

Molarity of
`HCl = 2.0 mol/L` (given)

Volume of
`HCl = 20 mL` (given)

Since, 1 mL= 0.001 L

So, volume of
`HCl = 0.02 L`

The volume of
`NaOH` can be determined using equation:

`M_(NaOH)V_(NaOH) = M_(HCl)V_(HCl)`

Substituting the values:

`0.5 mol/L* V_(NaOH) = 2.0 mol/L* 0.02L`

`V_(NaOH) = (2.0 mol/L* 0.02L)/(0.5 mol/L) = 0.08 L`

Since, 1 L = 1000 mL

So, the volume of
`NaOH` =
`80 mL`.

Hence, 80 mL of a 0.5 mol/L
`NaOH` solution required to completely react with 20 mL of a 2.0 mol/L
`HCl` solution.