Question

If 65.5 ml of HCl stock solution is used to make 450 ml of a 0.675 M HCl dilution, what is the molarity of the stock solution ?

Answer 1

Answer: The molarity of the stock solution is 4.64 M

Explanation:

To calculate the molarity of the diluted 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 stock solution

$M_2\text{ and }V_2$ are the molarity and volume of diluted solution

We are given:

$M_1=?M\\V_1=65.5mL\\M_2=0.675M\\V_2=450mL$

Putting values in above equation, we get:  

$M_1\times 65.5=0.675\times 450\\\\M_1=4.64M$

Hence, the molarity of the stock solution is 4.64 M