posted by Paul .
74.0 mL of a 1.80 M solution is diluted to a volume of 248 mL. A 124-mL portion of that solution is diluted using 135 mL of water. What is the final concentration?
1.80M x (74.0/248) x (124.0/259)= ? and that's assuming that the 124 mL + 135 mL are additive (to make a solution of 259 mL). Some solutions are not additive.