posted by lolo on .
a 0.120 ml portion of a 50.0% (w/w) KOH solution having a density of 1.50*10^3 g/l is diluted to 250 ml. What is the pH of the resulting solution?
50% w/w KOH means 50 g KOH/100 g solution.
Convert 50 g KOH to mols. mol = grams/molar mass.
Convert 100 g soln (mass) to volume using the density; I would convert that density you have in the problem to g/mL first.
Then M = mols/L soln for the original solution = ?. After dilution it is
M = ?M x original volume/250 (I wonder if that is really 0.120 mL).
Calculate OH^- and pOH, then convert to pH from that.