Question

What volume of a 1.25 M potassium

fluoride (KF) solution would be
needed to make 455 mL of a 0.838
M solution by dilution?
[?] mL of 1.25 M KF

Answer 1

305.032 mL of 1.25 M KF

Step-by-step explanation:

To calculate the volume of 1.25 M potassium fluoride (KF) solution needed to make 455 mL of a 0.838 M solution by dilution, we can use the dilution formula.

Dilution formula

`\boxed{\sf C_1V_1=C_2V_2}`

where:

• C₁ = Initial concentration
• V₁ = Initial volume
• C₂ = Final concentration
• V₂ = Final volume

In this case, we are diluting the 1.25 M potassium fluoride (KF) solution to a concentration of 0.838 M, where the final volume is 455 mL, so:

• C₁ = 1.25 M
• C₂ = 0.838 M
• V₂ = 455 mL

Substitute these values into the formula and solve for V₁:

`\implies \sf 1.25\;M \cdot V_1=0.838\; M \cdot 455\;mL`

`\implies \sf V_1=(0.838\; M \cdot 455\; mL)/(1.25\;M)`

`\implies \sf V_1=305.032\;mL`

Therefore, we need 305.032 mL of the 1.25 M potassium fluoride (KF) solution to make 455 mL of a 0.838 M solution by dilution.