“A Clear Vision, Backed By Definite Plans, Gives You A Tremendous Feeling Of Confidence And Personal Power.” – Brian Tracy
A solution is a homogenous mixture that contains a solvent and a solute. A solvent is that substance which is present in the larger amount in solution and solute is a substance which is present in a smaller amount. There are some various common examples of solutions that you see in your daily life.
Other than these, there are several other examples as well which are very common for household purposes:
There are various kinds of binary solutions exist in nature as given in the table below:
Types of Solutions |
Solvent |
Solute |
Examples |
Gaseous |
Gas |
Gas |
Mixture of Oxygen and Nitrogen |
Gas |
Liquid |
Humidity |
|
Gas |
Solid |
Camphor in Nitrogen gas |
|
Liquid |
Liquid |
Gas |
Carbon dioxide in Water |
Liquid |
Liquid |
Milk dissolved in water |
|
Liquid |
Solid |
Sugar dissolved in water |
|
Solid |
Solid |
Gas |
Hydrogen in Palladium |
Solid |
Liquid |
An amalgam of mercury with sodium |
|
Solid |
Solid |
Brass (an alloy of copper and zinc) |
(i) Solubility: The maximum ability of a substance to get completely dissolved in a solvent. When the solute is solid and the solvent is liquid, then the only temperature affects the solubility. With the increase in temperature, the solubility increases. But pressure has no effect in this case as both solids and liquids are incompressible. But is the solute is gas, then pressure also is an important factor that plays major role insolubility. For this case, Henry's law is given which states that - "At constant temperature, the solubility of a gas is directly proportional to the partial pressure of a gas present above the solution".
(ii) Vapour pressure of liquid solutions: In this concept, you learn that the vapour pressure of volatile liquids in solution when taken in a closed vessel. This phenomenon is explained by Raoult's law, which states that - "The vapour pressure of each volatile liquid present in the solution is directly proportional to the mole fraction of that liquid present in solution".
Mathematically, Raoult's law can be expressed as follows:
where, vapour pressure of pure component 1
= vapour pressure of pure component 2
= mole fraction of component 2
(iii) Ideal and non-ideal solutions: Ideal solutions are those solutions which obey Raoult's law at all ranges of concentrations. Whereas the non-ideal solutions are those which do not obey Raoult's law at all range of concentrations. The vapour pressure of non-ideal solutions are always higher or lower than as predicted by Raoult's law and thus we say that the solution is exhibiting the positive or negative deviation, respectively.
(iv) Colligative properties: The properties of solutions which depend only on the number of solute particles present in the solution are known as colligative properties.
Abnormal Mass: This concept says, that when a solute is dissolved in a liquid then the solute does not dissociate completely as expected instead it dimerizes and thus the molar mass of solute become double. Such deviation of molar mass from the actual value is known as abnormal molar mass.
To deal with the case of an abnormal mass, a Vant Hoff factor was introduced in 1880, which mathematically is described as follows:
Chapters No. |
Chapters Name |
Chapter 1 |
|
Chapter 2 |
|
Chapter 3 |
|
Chapter 5 |
|
Chapter 6 |
|
Chapter 7 |
|
Chapter 8 |
|
Chapter 9 |
|
Chapter 10 |
|
Chapter 11 |
|
Chapter 12 |
|
Chapter 13 |
|
Chapter 14 |
|
Chapter 15 |
|
Chapter 16 |
|
Chapter 17 |
|
Chapter 18 |
|
Chapter 19 |
|
Chapter 20 |
|
Chapter 21 |
|
Chapter 22 |
|
Chapter 23 |
|
Chapter 24 |
|
Chapter 25 |
|
Chapter 26 |
|
Chapter 27 |
|
Chapter 28 |
The degree of dissociation of a weak electrolyte,
is related to van’t Hoff factor
by the expression
Ethylene glycol is used as an antifreeze in a cold climate. Mass of ethylene glycol which should be added to 4 kg of water to prevent it from freezing at – 6°C will be :
804.32 g
204.30 g
400.00 g
304.60 g
A 5.2 molal aqueous solution of methyl alcohol, CH3OH, is supplied. What is the mole fraction of methyl alcohol in the solution ?
0.100
0.190
0.086
0.050