Question

A chemist must prepare 275. mL of 1967, ?? aqueous copper(II) fluoride (Cur) working solution. He'll do this by pouring out some 2.63 T-aqueous copper(II) fluoride stock solution into a graduated cylinder and diluting it with distilled water. Calculate the volume in mL of the copper(II) fluoride stock solution that the chemist should pour out. Be sure your answer has the correct number of significant digits mL

Answer 1

206 mL

Step-by-step explanation:

In the annexed picture you can see your same question, just in another format.

First we calculate the total moles of CuF₂ that are required in the working solution:

1967 μM ⇒ 1967 / 10⁶ = 1.967 x10⁻³M

1.967 x10⁻³M * 0.275 L = 5.409x10⁻⁴ mol

Now we divide those moles by the concentration of the stock solution, to calculate the volume:

5.409x10⁻⁴ mol ⇒ 5.409x10⁻⁴ * 1000 = 0.5409 mmol

0.5409 mmol ÷ (2.63 mmol/L) = 0.206 L

0.206 L ⇒ 0.206 * 1000 = 206 mL