Question

In Lab 11 you make a stock solution of salicylic acid, and then four dilutions. The stock solution is made by diluting 10.00 ml of 1.250 x 10^-2 M salicylic acid in 100.00 mL of solution. You then make the four dilutions as follows:

Dilution #1 = 40.00 mL of stock diluted to 100.00 mL
Dilution #2 = 30.00 mL of stock diluted to 100.00 mL
Dilution #3 = 20.00 mL of stock diluted to 100.00 mL
Dilution #4 = 10.00 mL of stock diluted to 100.00 mL

Please show your work with some explanation. Thank you!

Answer 1

Dilution

Using,

final concentration = initial concentration x initial volume/final volume

concentration of stock solution = 1.250 x 10^-2 M x 10 ml/100 ml = 1.250 x 10^-3 M

Dilution #1,

concentration of final solution = 1.250 x 10^-3 M x 40 ml/100 ml = 5.00 x 10^-4 M

Dilution #2,

concentration of final solution = 1.250 x 10^-3 M x 30 ml/100 ml = 3.75 x 10^-4 M

Dilution #3,

concentration of final solution = 1.250 x 10^-3 M x 20 ml/100 ml = 2.50 x 10^-4 M

Dilution #4,

concentration of final solution = 1.250 x 10^-3 M x 10 ml/100 ml =1.250 x 10^-4 M