A: A student must make a five-fold dilution of a 2.15 M HCl solution. If the student wishes to make 75.0 mL of the diluted solution, what volume of the 2.15 M solution will he need to dilute?

Question

A: A student must make a five-fold dilution of a 2.15 M HCl solution.  If the student wishes to make 75.0 mL of the diluted solution, what volume of the 2.15 M solution will he need to dilute?

B: What is the concentration of the diluted substance?

DrBob222 · Answer

Isn't a five fold dilution just making the solution more dilute by a factor of 5? So 2.15M/5 = 0.43M 75 mL x 0.43M = mL x 2.15 M Solve for mL of the 2.15M solution to use.