Question

How many liters of a 2.5 M solution will you need toproduce 75 mL of a 1.75 M solution

Answer 1

0.0525 L.

Step-by-step explanation:

What is given?

Volume 2 (V2) = 75 mL,

Concentration 1 (C) = 2.5 M.

Concentration 2 (C2) = 1.75 M,

What do we need? Volume 1 (V1).

Step-by-step solution:

First, let's convert 75 mL to L. Remember that 1 L equals 1000 mL:

`75\text{ mL}\cdot\frac{1\text{ L}}{1000\text{ mL}}=0.075\text{ L.}`

To solve this problem we have to use the following formula:

`C_1V_1=C_2V_2.`

Where C is concentration, V is volume, subindex 1 is the initial volume and concentration of the solution, and subindex 2 is the final volume and concentration of the solution.

We want to find the initial volume (V1), so we just have to solve for 'V1' and replace the data that we have (remember to put the volume in liters):

`\begin{gathered} V_1=(C_2V_2)/(C_1)=\frac{1.75\text{ M}\cdot0.075\text{ L}}{2.5\text{ M}}, \\ \\ V_1=0.0525\text{ L.} \end{gathered}`

The answer would be that we need 0.0525 L.