A solution is prepared by dissolving 21.0 grams of K2CO3 in 96.0 grams of water. The solution has a density of 1.17 g/ml. calculate the molarity of the solution. the first thing i did was to add 96 and 21 grams to get 117 grams as the weight of the solution...and from there i was stuck. would i divide 117 by 1.17 to get a 100 ml solution? then ...
thanks in advance!
2007-12-03 09:46:17 · 2 answers · asked by chrissymoo7 3 in Science & Mathematics ➔ Chemistry
Molarity is the number of moles of solute dissolved in one liter of solution.
K2CO3 ==> 2*39.098 + 12.01 + 3*16 =
138.206 g/mol
(21 g / 138.206 g/mol) / (100 ml)(1 L/ 1000 ml) =
(21 g / 138.206 g/mol) / (0.100 L) ≈ 1.52 M
2007-12-04 06:10:46 · answer #1 · answered by Helmut 7 · 0⤊ 0⤋
Ok so .5M means .5mol/1000ml So you can set up a ratio = (.5mol/1000ml)=(.4mol/xml) and cross multiply to get .5x=400 then solve for x x = 800ml Not the most conventional way of doing it, but its always worked for me
2016-04-07 06:29:35 · answer #2 · answered by Anonymous · 0⤊ 0⤋