00:01
Dear students, question is, a solution contains 22 .4 gram of nhl and 0 .38 kg of water at 20 degrees celsius.
00:10
What is the vapor pressure of the solution if vapor pressure of pure water is 23 .7 tar at the same temperature? so here we have vapor pressure of pure water at p0 is 23 .7 tar.
00:30
We have to find out the vapor pressure of solution ps.
00:36
Here, mass of nacl is 22 .4 gram and mass of water is 0 .388 kilogram.
00:49
We'll find their number of moles.
00:52
So, nacl, 22 .4 equal to 22 .4 gram, this is equal to 5 .5, its molar mass, which is give us number of moles it is 0 .383 then moles of water equal to mass of water is 0 .388 kg which is equal to 388 gram which is equal to 388 divided by 18 which is equal to it is 21 .556 so these are the moles of initial and moles of quarter let us find out its mole fraction.
01:47
Therefore, mole fraction of water equal to mole of water that is 21 .55 by total number of moles, 0 .383 plus 21 .556, which is equal to it is nearly 0 .983...