Question

You need to prepare .200M solution of hydrochloric acid (HCl). If you took out .830ml of the 12.0M stock solution. How much water must you add to make the .200M diluted solution?

Answer 1

You must add 48.97 mL of water to make the 0.200 M diluted solution.

Step-by-step explanation:

In chemistry, dilution is the reduction in concentration of a chemical in a solution. In other words, it is the process of reducing the concentration of solute in solution, simply adding more solvent to the solution.

In a dilution, the quantity or mass of the solute is not changed but only that of the solvent. As only solvent is being added, by not increasing the amount of solute the concentration of the solute decreases.

The expression for the dilution calculations is:

Cinitial* Vinitial = Cfinal* Vfinal

In this case:

• Cinitial= 12 M
• Vinitial= 0.830 mL
• Cfinal= 0.200 M
• Vfinal= ?

Replacing:

12 M*0.830 mL= 0.200 M*Vfinal

Solving:

`Vfinal=(12 M*0.830 mL)/(0.200 M)`

Vfinal= 49.8 mL

Since 0.830 mL is the volume you initially have of HCl, the amount of water you must add is:

49.8 mL - 0.830 mL= 48.97 mL

You must add 48.97 mL of water to make the 0.200 M diluted solution.