Answer:
[tex]\large\boxed{\large\boxed{0.64M}}[/tex]
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:
[tex]Molarity=\dfrac{\text{moles of solute}}{\text{volume of the solution in liters}}[/tex]
Then, since the moles of solute is the same for both the mother solution and the diluted solution:
[tex]\text{Molarity mother solution }\times\text{ volume mother solution}=\\\\=\text{Molarity diluted solution }\times\text{ volume diluted solution}[/tex]
Substitute and solve for the molarity of the diluted solution:
[tex]250mL\times 0.75M=(45mL+250mL)\times M\\\\\\M=\dfrac{250mL\times 0.75M}{295mL}=0.64M[/tex]
