How do you convert from #%"w/v"# to molarity?
1 Answer
May 15, 2017
We define
#%"w/v" = "solute mass in g"/"solution volume in mL" xx 100%#
By unit conversion, we have that
#m_(solute)# for the solute mass in#"g"# #V_(soln)# for the solution volume in#"mL"# #M_(solute)# for the molar mass of the solute in#"g/mol"#
Therefore:
#"Molarity" = (m_(solute)/V_(soln) xx 100%) xx (1000 "mL/L")/(100% xx M_(solute))#
Or, rewriting in terms of
#bb("Molarity" ("mol"/"L") = 1000/(M_(solute))(%"w/v")/(100%))#
As an example, if we have a
#color(blue)("Molarity" ("mol"/"L")) = 1000/(36.4609) (37cancel(%) "w/v")/(100cancel(%))#
#=# #color(blue)("10.15 mol/L")#