# A stock solution of hydrochloric acid with 1.25 M, 25 mL was diluted to 75 mL with water. What was the new concentration of this diluted acid?

Jun 21, 2018

0.42 M

#### Explanation:

To calculate the new concentration, we'll use the dilution formula

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

${M}_{1}$ = Concentration of stock solution = 1.25 M
${M}_{2}$ = Concentration of diluted solution = ?
${V}_{1}$ = Volume of stock solution = 25 mL
${V}_{2}$ = Volume of diluted solution = 75 mL

${M}_{1}$${V}_{1}$ = ${M}_{2}$${V}_{2}$
$1.25$ x $25$ = ${M}_{2}$ x $75$
${M}_{2}$ = $0.42 \text{M}$