What is the molality of a solution that contains 31.0 g #HCl# in 5.00 kg water?

1 Answer
Jan 22, 2016

Answer:

#"Molality"# #=# #("moles of solute")/("kg of solvent")#

Explanation:

As you know, this unit is independent of volume, and depends solely on the amount of substance (in moles) with respect to mass of solvent.

As to your problem:

#"Molality"# #=# #("moles of solute")/("5 kg")#

#=# #((31.0*g)/(36.46*g*mol^-1))/(5.00*kg)~=0.2*mol*kg^-1#

Assuming that the volume of solution changes marginally (a safe assumption) what is the estimated concentration in #mol*L^-1#?