Chapter 14, Problem 79A

If you dilute 20.0 mL of a 3.5M solution to make100.0 mL of solution, what is the molarity of the dilutesolution?

Interpretation Introduction

Interpretation:

The molarity of diluted solution have to be calculated.

Concept introduction:

The equation for dilution is

$\begin{array}{l} M_1{V}_1=M_2{V}_2\hfill \\ Stocksolution=Dilutedsolution\hfill \end{array}$

Concentrated solutions of known molarities are known as stock solution.

Where,

M₁ = molarity of the stock solution V₁ = volume of stock solution

M₂ = molarity of the diluted solution V₂ = volume of diluted solution

Answer to Problem 79A

The molarity of diluted solution is 0.7 M.

Explanation of Solution

Data given:

M₁ = molarity of the stock solution = 3.5 M

V₁ = volume of the stock solution = 20 mL

V₂ = volume of diluted solution = 100 mL

$\begin{array}{l} M_1{V}_1=M_2{V}_2\hfill \\ Stocksolution=Dilutedsolution\hfill \end{array}$

$\begin{array}{l}Molarityofthedilutedsolution=M_2=\frac{M_1{V}_1}{V_2}\\ M_2=\frac{3.5M\times 20mL}{100mL}=0.7M\end{array}$