I have 345 mL of a 1.5 M NaCl solution. If I boil the water until the volume of the solution is 250 mL, what will the molarity of the solution be?

1 Answer
Feb 8, 2016

Answer:

The amount of substance, of #NaCl# solute is constant. The answer is approx. #2# #mol*L^-1#.

Explanation:

#"Concentration"# #=# #"Mass"/"Volume of solution"#

Initially I had #0.345*cancelLxx1.5*mol*cancel(L^-1)# #=# #0.518# #mol#.

After I boil off some of the water, I have a new volume of solution but the SAME amount of SOLUTE, i.e. #0.518# #mol#.

Thus #"Concentration"# #=# #(0.518*mol)/(0.250*L)# #=# #??mol*L^-1#