Question

If 45 mL of water are added to 250 mL of a 0.75 M K2SO4 solution, what will the molarity of the diluted solution be?

Answer 1

`\large\boxed{\large\boxed{0.64M}}`

Step-by-step explanation:

When you form a diluted solution from a mother (concentrated) solution, the moles of solute are determined by the mother solution.

The main equation is:

`Molarity=\frac{\text{moles of solute}}{\text{volume of the solution in liters}}`

Then, since the moles of solute is the same for both the mother solution and the diluted solution:

`\text{Molarity mother solution }*\text{ volume mother solution}=\\\\=\text{Molarity diluted solution }*\text{ volume diluted solution}`

Substitute and solve for the molarity of the diluted solution:

`250mL* 0.75M=(45mL+250mL)* M\\\\\\M=(250mL* 0.75M)/(295mL)=0.64M`