# Calculate the amount of 1 M NaOH aqueous solution needed to make 100 mL of 0.5 M NaOH aqueous solution.

##### 1 Answer
Sep 26, 2014

You need 50 mL of 1 mol/L NaOH.

${c}_{1} {V}_{1} = {c}_{2} {V}_{2}$

${c}_{1}$ = 1 mol/L; ${V}_{1}$ = ?
${c}_{2}$ = 0.5 mol/L; ${V}_{2}$ = 0.100 L

V_1 = V_2 × c_2/c_1 = $\text{0.100 L" × "0.5 mol/L"/"1 mol/L}$ = 0.05 L = 50 mL

You need 50 mL of 1 mol/L NaOH to make 100 mL of 0.5 mol/L NaOH.