posted by cheri .
A sample of 7.45 grams of NaOH is dissolved
into 609 mL of aqueous 0.250 M NaOH (as-sume no volume change). This solution is
then poured into 2.18 gallons of water. (You
may assume that the two volumes can be
added.) What is the concentration of NaOH
in the final solution?
Answer in units of M
7.45 g NaOH is how many mols? That's mol = grams/molar mass = ?.
609 mL of 0.250M NaOH is how many mols? That's M x L = ?
Add to obtain total mols.
Then convert 2.18 gallons to L, add to the 609 mL to obtain total volume. Then M final soln = total mols/total L solution.