Question

What volume of 1m mgcl2 stock solution will be needed to prepare 50 ml of 25 mm solution?

Answer 1

Answer: Volume of  1m $MgCl_2$ stock solution needed to prepare 50 ml of 25 mm solution is 1.25 ml.

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

According to the neutralization law,

$M_1V_1=M_2V_2$

where,

$M_1$ = molarity of stock $MgCl_2$ solution = 1 M

$V_1$ = volume of stock $MgCl_2$ solution = ?

$M_2$ = molarity of dilute $MgCl_2$ solution = 25 mM= 0.025 M

$V_2$ = volume of dilute $MgCl_2$ solution = 50 ml

$1\times V_1=0.025\times 50$

$V_1=1.25ml$

Therefore, the volume of  1m $MgCl_2$ stock solution needed to prepare 50 ml of 25 mm solution is 1.25 ml