Mixture

IMPORTANT

Mixture: Overview

This Topic covers sub-topics such as Mixtures, Matter, Alloys, Homogeneous Mixture, Pure Substances, Types of Mixtures, Chemical Classification of Matter and, Nature of Alloys

Important Questions on Mixture

HARD

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 1

What is the difference between an alloy and a metalloid?

MEDIUM

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 2

Pure gold is very soft and therefore not suitable for making jewellery. To make it hard, gold is alloyed with other metals. The purity of gold is measured in carats according to the table below. Carat number is the number of parts of gold in $24$ parts.

Carat number	Number of parts of gold in $24$ parts	Number of parts of other metals in $24$ parts
$24$	$24$	$0$
$22$	$22$	$2$
$18$	$18$	$6$
$14$	$14$	$1$
$12$	$12$	$12$

(a) What is the percentage of gold in $18$ carat gold? Name any two metals that are used to make $22$ carat gold.

b) (i) What type of mixture is an alloy?

(ii) How does the electrical conductivity of an alloy compare with that of the pure metal?

MEDIUM

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 3

Carat number	Number of parts of gold in $24$ parts	Number of parts of other metals in $24$ parts
$24$	$24$	$0$
$22$	$22$	$2$
$18$	$18$	$6$
$14$	$14$	$1$
$12$	$12$	$12$

(a) What is the percentage of gold in $18$ carat gold? Name any two metals that are used to make $22$ carat gold.

(b) Like gold, pure iron is also comparatively soft and also undergoes rusting. Name the substance that is mixed with iron.

(i) to make it hard

(ii) to change it to stainless steel to prevent rusting.

MEDIUM

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 4

Do impure substances have fixed Melting point ,boiling point etc?

EASY

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 5

Why alloys doesn't burn easily

MEDIUM

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 6

What does homogeneous mean?

EASY

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 7

What does uniformly distributed means in a homogeneous mixture?

MEDIUM

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 8

Match the alloys in column A with their constituent elements in Column B.
Column A Column B
1. Invar A Pb, Sn
2. Gunmetal B Pb, Sb, Sn
3. Brass C Cu, Sn, Zn, Pb
4. Solder D Fe, Ni, C
5. Type metal E Cu, Zn
Choose an appropriate match-

EASY

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 9

The atmosphere mainly consists of nitrogen and oxygen. Which term describes the combination of gases in the atmosphere?

MEDIUM

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 10

Differentiate between homogeneous and heterogeneous mixtures.

EASY

IMPORTANT

science>Is Matter around Us Pure?>Mixture> Q 11

Air is a mixture but various gases, particles, _____ keep on adding in air in various proportions at different places.