A 2400-gram sample of an aqueous solution contains 0.012 gram of #NH_3#. What is the concentration of #NH_3# in the solution, expressed as parts per million?

1 Answer
Mar 11, 2016

#"Parts per million "= " Milligram per litre of solution"#. The concentration of the solution is #5# #"ppm"#.

Explanation:

At #"ppm"# concentrations, we don't have to bother with consideration of the density of the solvent versus the density of the solution; in any case we don't have these details.

There are #12xx10^-3# #g# ammonia in a #2400# #g# mass of solution. We assume (reasonably) that the volume of the solution is #2.400*L#.

So #"concentration"# #=# #(12xx10^-3gxx10^3*mg*g^-1)/(2.400*L)# #=# #(12*mg)/(2.400*L)# #=# #5*mg*L^-1# #=# #5# #"ppm"#