Answer:- 544.5 mL of water need to be added.
Solution:- It is a dilution problem. The equation used for solving this type of problems is:
[tex]M_1V_1=M_2V_2[/tex]
where, [tex]M_1[/tex] is initial molarity and [tex]M_2[/tex] is the molarity after dilution. Similarly, [tex]V_1[/tex] is the volume before dilution and [tex]V_2[/tex] is the volume after dilution.
Let's plug in the values in the equation:
[tex]1.25M(363mL)=0.50M(V_2)[/tex]
[tex]V_2=\frac{1.25M(363mL)}{0.50M}[/tex]
[tex]V_2=907.5mL[/tex]
Volume of water added = 907.5mL - 363mL = 544.5 mL
So, 544.5 mL of water are need to be added to the original solution for dilution.