Question

2.5g of Na2co3 dissolved in 100ml of water calculate molarity and molality ?(density of solution =1g/ml​

Answer 1

Answer:

After studying this Unit, you will be

able to

• describe the formation of different

types of solutions;

• express concentration of solution

in different units;

• state and explain Henry’s law and

Raoult’s law;

• distinguish between ideal and

non-ideal solutions;

• explain deviations of real solutions

from Raoult’s law;

• describe colligative properties of

solutions and correlate these with

molar masses of the solutes;

• explain abnormal colligative

properties exhibited by some

solutes in solutions.

In normal life we rarely come across pure substances.

Most of these are mixtures containing two or more pure

substances. Their utility or importance in life depends

on their composition. For example, the properties of

brass (mixture of copper and zinc) are quite different

from those of German silver (mixture of copper, zinc

and nickel) or bronze (mixture of copper and tin);

1 part per million (ppm) of fluoride ions in water

prevents tooth decay, while 1.5 ppm causes the tooth

to become mottled and high concentrations of fluoride

ions can be poisonous (for example, sodium fluoride is

used in rat poison); intravenous injections are always

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.

SolutionsSolutions Solutions

Almost all processes in body occur in some kind of liquid solutions.

Objectives

2.1 Types of Types ofTypes of

Solutions SolutionsSolutions

2

Unit

2

Solutions are homogeneous mixtures of two or more than two

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.,