Page 232 - Chemistry ICSE Class IX

5 Percentage Composition

of a Mixture

BASIC CONCEPTS

SUBSTANCE
A kind of matter that cannot be separated into other kinds of matter by any physical process is called a
substance. A substance can be an element or a compound.

MlXTURE

y A OKZVWTG is that form of matter in which two or more substances are simply mixed in any proportion.
y The constituents of a mixture are also called the EQORQPGPVU QH C OKZVWTG.

y Mixtures do not have a fixed composition.
y The constituents of a mixture can be separated by simple laboratory methods.
y Mixtures which are uniform in its composition and properties throughout are called JQOQIGPGQWU
OKZVWTGU.
'ZCORNGU Solution of sugar in water, Mixture of gases, etc.
y Mixtures which are not uniform in its composition and properties are called JGVGTQIGPGQWU OKZVWTGU.
'ZCORNGU Sand + Sugar, Muddy water.

PERCENTAGE COMPOSITION OF A MIXTURE
The relative amounts of the various components of a mixture can be described by their mass percentages
(% by mass). For a mixture containing two substances A and B, the mass percentage of each can be calculated
by using the relationships,
Mass of A
Mass percent of A = × 100
Mass of A + Mass of B

Mass of B
Mass percent of B = × 100
Mass of A + Mass of B

EXPERIMENT 5.1

Objective
6Q FGVGTOKPG VJG RGTEGPVCIG EQORQUKVKQP QH C OKZVWTG EQPVCKPKPI UCPF CPF UCNV

Procedure

Follow the steps given below to perform this experiment: