Posted by Anonymous on Monday, March 21, 2011 at 2:16pm.
A: A student must make a fivefold 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?

Chemistry  DrBob222, Monday, March 21, 2011 at 6:41pm
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.