Question

In a laboratory preparation room one may find a reagent bottle containing 5.0 L of 12 M NaOH. Write a set of instructions for the production of 250 mL of 3.5 M NaOH from such a solution.

Answer 1

Answer: The volume taken from the reagent bottle must be 72.91 mL

Explanation:

To calculate the volume of concentrated solution, we use the equation:

$M_1V_1=M_2V_2$

where,

$M_1\text{ and }V_1$ are the molarity and volume of the concentrated solution  which is the reagent bottle.

$M_2\text{ and }V_2$ are the molarity and volume of diluted solution which is the solution to be prepared.

We are given:

$M_1=12M\\V_1=?mL\\M_2=3.5M\\V_2=250mL$

Putting values in above equation, we get:

$12\times V_1=3.5\times 250\\\\V_1=72.91mL$

Hence, the volume taken from the reagent bottle must be 72.91 mL