NCERT Book Class 12 Chemistry Chapter 1 Solutions

Unit

Objectives
1
Solutions
After studying this Unit, you will be
able to
· describe the formation of different Almost all processes in body occur in some kind of liquid solutions.
types of solutions;
· express concentration of solution
in different units; In normal life we rarely come across pure substances.
· state and explain Henry’s law and Most of these are mixtures containing two or more pure
Raoult’s law; substances. Their utility or importance in life depends
· distinguish between ideal and on their composition. For example, the properties of
non-ideal solutions; brass (mixture of copper and zinc) are quite different
· explain deviations of real solutions from those of German silver (mixture of copper, zinc
from Raoult’s law; and nickel) or bronze (mixture of copper and tin);
· describe colligative properties of 1 part per million (ppm) of fluoride ions in water
solutions and correlate these with prevents tooth decay, while 1.5 ppm causes the tooth
molar masses of the solutes; to become mottled and high concentrations of fluoride
· explain abnormal colligative ions can be poisonous (for example, sodium fluoride is
properties exhibited by some used in rat poison); intravenous injections are always
solutes in solutions. dissolved in water containing salts at particular ionic
concentrations that match with blood plasma
concentrations and so on.
In this Unit, we will consider mostly liquid
solutions and their formation. This will be followed by
studying the properties of the solutions, like vapour
pressure and colligative properties. We will begin with
types of solutions and then various alternatives in
which concentrations of a solute can be expressed in
liquid solution.

1.1 Types of Solutions are homogeneous mixtures of two or more than two
Solutions components. By homogenous mixture we mean that its composition
and properties are uniform throughout the mixture. Generally, the
component that is present in the largest quantity is known as solvent.
Solvent determines the physical state in which solution exists. One or
more components present in the solution other than solvent are called
solutes. In this Unit we shall consider only binary solutions (i.e.,