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

Question

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

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Answer 1 · 2017-02-02T15:42:23

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

#"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"#?