# If 2.50 mL of a 1.31 M solution is diluted to 90.0 mL, what is the molarity of the new solution?

## Question:

If 2.50 mL of a 1.31 M solution is diluted to 90.0 mL, what is the molarity of the new solution?

## Molarity:

Molarity is a very common unit of measurement in chemistry and quantifies the moles of solute dissolved per liter of solution. The higher the molarity of a solution is, the more moles of solute are present per liter. In other words, the higher the molarity is, the higher the concentration is.

## Answer and Explanation: 1

We are given:

- Initial volume of solution: 2.50 mL
- Initial concentration of solution: 1.31 M
- Final volume of solution: 90.0 mL

To find the molarity of the diluted solution, we can use the following formula:

{eq}\rm c_1V_1 = c_2V_2 {/eq}

Where:

{eq}\rm
c_1
{/eq} is the initial concentration

{eq}\rm V_1
{/eq} is the initial volume

{eq}\rm c_2
{/eq} is the final concentration

{eq}\rm V_2
{/eq} is the final volume

We can easily modify the equation to make {eq}\rm c_2 {/eq} the subject of the formula by dividing both sides by {eq}\rm V_2 {/eq}:

{eq}\begin{align} \rm c_2 =& \rm \dfrac{c_1V_1}{V_2}\\ &= \rm \dfrac{(1.31\:M)(2.50\:mL)}{90.0\:mL}\\ &= \rm 0.0364\:M \end{align} {/eq}

**The concentration is 0.0364 M.**

#### Learn more about this topic:

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Chapter 8 / Lesson 4What is molarity? What is molality? Compare molarity vs molality by viewing molality and molarity formulas, how to calculate molarity and molality, and examples.