a mixture of NaCl and sucrose that has a combined mass of 10.20g is dissolved in enough water to make up to a 250mL solution. osmotic presdure of solution is 7.32atm at 23℃. calculate the mass percent of NaCl

Answer 1

I believe this is a two equation to be solved simultaneously problem. I suppose you want mass % NaCl IN THE SAMPLE.
Let x = g NaCl
and y = g sucrose
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eqn 1 is x + y = 10.20

pi = iMRT.
Substitute pi, i, R, and T and solve for M. Remember i for NaCl is 2 and sucrose is 1. Then M x 0.250 = z mols
Use mols to set up eqn 2.
(x/mm NaCl) + (y/mm sucose) = z mols. where mm is molar mass.

Solve for x and y, then convert x to weight percent.
%NaCl = (mass NaCl/10.20)*100 = ?