Page 39 - ICSE Chemistry 6

MIXTURES

A physical combina on of two or more elements or compounds in any propor on is called a mixture.
In a mixture, original atoms and molecules remain as they are because no chemical change is taking place.
In a mixture, components are loosely held together, they retain their individual proper es and may be
present in any propor on. For example, lemonade is a mixture. It contains water, salt, sugar and lemon
juice. When we drink lemonade, we get the taste of all its cons tuents.

Mixtures are impure substances because their cons tuents have diff erent kinds of molecules. Milk is a
mixture. It consists of fats, carbohydrates, proteins, salts, vitamins and water.
Activity 2.3

Aim: To iden fy mixtures that we come across in our daily lives

We use a number of mixtures in our daily lives. List some mixtures that you can recall. Iden fy the
components of these mixtures and present the data in a tabular format.

Characteristics of a Mixture

• The cons tuents in a mixture may be present in any ra o. The composi on of a mixture can be
changed by changing the propor on of its cons tuents.
Example: In a mixture of sugar and water, the quan ty of sugar and water is not fi xed. A glass of
water may contain one spoonful, two spoonfuls or three spoonfuls of sugar. However, each of
these samples is considered to be a mixture of sugar and water.
• The cons tuents of a mixture exhibit their original proper es. Thus, the mixture has no property
of its own.
Example: The taste of sugar is sweet and it remains the same even when it is mixed with water.
• There is no fi xed mel ng or boiling point of a mixture.
Example: The boiling point of a mixture of a glass of water and one spoonful of sugar will diff er
from the boiling point of a mixture of same quan ty of water and four spoonfuls of sugar.
• A mixture can be separated into its cons tuents by simple physical or mechanical means.
Example: We can separate salt from iron dust by using a magnet.
• Generally, no energy is absorbed or released when a mixture is formed.

Types of Mixtures

In our day-to-day lives, we come across diff erent types of mixtures. In some mixtures, the components
can be easily dis nguished, while in some cases, the components are not clearly visible.

Hence, mixtures are divided into two main types.
1. Homogeneous mixtures 2. Heterogeneous mixtures

Homogeneous Mixture

A mixture in which the components cannot be seen separately and are uniformly distributed throughout its
volume are called homogeneous mixture. Salt solu on and sugar solu on are examples of homogeneous
solu ons.

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