posted by niki .
at 40 degree C , the vapour pressure of water is 55.3 mm of hg. calculate the vapour pressure at same temp. of 10%aques solution of urea??
PH2O = Xsoln*PoH2O
10% urea = 10g urea/(10g urea+90g H2O)
moles urea = grams/molar mass urea.
moles H2O = grams/molar mass H2O.
XH2O = moles H2O/total moles.
Then plug this X for H2O into the equation at the top, multiply by 55.3 mm.
The first equation should read this way.
Psoln = XH2O*PoH2O