Question

what is raoult's law? can anyone explain with suitable example...?

Answer 1

Here is a link to the Wikipedia article.
http://en.wikipedia.org/wiki/Raoult's_law

Is there anything in the article that is not making sense to you?

Answer 2

Raoult's law basically states that if you a nonvolatile solute in a solution, this will cause the solution to evaporate more slowly.

Imagine a boat in the ocean. Water cannot evaporate through a boat, so the more boats we have, the slower the ocean evaporates. Water vapor can still condense on the boat and flow back into the ocean.

The more nonvolatile solute you have in a solution, the more it gets in the way of evaporation. Here is the equation for Raoult's law:\[P_A=X_AP_A^0 \quad \bigg| \quad P_A=vapor \space pressure \space of \space A \quad \bigg| \quad X_A = mole \space fraction\]\[P_A^0=vapor \space pressure \space of \space pure \space A\]
If the solution contains only a single nonvolatile solute (B), then:\[X_A+X_B=1 \quad \bigg| \quad X_A = 1 - X_B \quad \bigg| \quad P_A=(1-X_B)P_A^0\]
You can rearrange to get an equation that gives the relationship between the mole fraction of the nonvolatile solute and the vapor pressure:\[P_A^0-P_A= \Delta P = X_BP_A^0\]

Answer 3

imagine that you yourself in a group of strangers... how would you behave?
you behave differently in that group of strangers than when you are with your friends.
<a simple analogy on the behavior of an ideal solution>