00:01
In this question, it has been given that at a temperature of 75 degrees centigrade, the vapor pressure of liquid a is 1 .75 atmosphere.
00:15
The vapor pressure of the liquid b is given as 0 .7 atmosphere.
00:24
The boiling point of a mixture of liquid a and b, that is a plus b the boiling point of this liquid mixture at a pressure of 0 .9 atmosphere has been given as 75 degree centigrade we have been asked to find the mole fraction the mole fraction of component a of component a it is denoted by kai a in the liquid mixture in the liquid mixture.
01:06
Now this is an application of the rowles law.
01:11
So according to the rowl's law, the value of p total, the total pressure is equal to p0a, which is the partial pressure of a, multiplied by chia which is the mole fraction of component a plus p .0b, that is the partial pressure of component b, multiplied by, by kai b which is the mole fraction of component b or we can simplify it as p t is or we can simplify it as p t is equal to p not b plus in the brackets we'll have p not a minus p not b and this whole is multiplied by kai a which is the mole fraction of component now we know that p t is the total pressure it is the total pressure total pressure and this has been given as 0 .9 atmosphere the value of p .a which is the partial pressure of component a is 1 .75 atmosphere p .0 b has been given as the vapor pressure of component b, that is 0 .7 atmosphere.
02:47
So placing the values in the given formula, we can say that 0 .9 is equal to 0 .7 plus.
02:56
In the brackets we'll have 1 .75 minus 0 .7 multiplied by kai.
03:04
On solving, we will get the value of kaia.
03:08
So we can say kai a will be equal to 0 .19.
03:14
So this is the mole fraction of component a in the liquid phase...