A #17.2*g# mass of ethylene glycol was dissolved in a #500*g# mass of water to give a solution of #515*mL# volume. What are....?

#"(i) Molarity..."#
#"(ii) Molality..."#
#"(iii) Percentage by mass..."#
#"(iv) Moles fractions of each component..."#

1 Answer
Feb 2, 2017

Answer:

#"Moles of solute"# #=# #(17.2*g)/(62.07*g*mol^-1)=0.277*mol#

Explanation:

#"Molarity"="Moles of solute"/"Volume of solution"=(0.277*mol)/(0.515*L)#

#~=0.50*mol*L^-1#

#"Molality"="Moles of solute"/"Kilograms of solvent"=(0.277*mol)/(0.500*kg)#

#~=0.50*mol*kg^-1#

#"Percentage by mass"# #=# #"Mass of solute"/"Mass of solution"xx100%#

#=(17.2*g)/(17.2*g+500*g)xx100%=3.33%(m/m)#

#"Mole fraction, "chi_"diol"# #=# #"Moles of diol"/"Moles of diol + moles of solvent"#

#=(0.277*mol)/(0.277*mol+(500*g)/(18.01*g*mol^-1))~=0.001#

What is #chi_"water"#?