Matter Around Us

Question 1

Not all things that we see or feel are matter. __________ They are not matter.

Answer 1

For example, sunlight, sound, force and energy neither occupy space nor have any mass.

Question 2

In the modern periodic table there are _____ elements known to us, ____ of which are naturally occurring while the remaining ______ have been artificially created. But from these 118 elements, billions of compounds are formed- some naturally occurring and some artificial. Isn’t that amazing?

Answer 2

118
92
26

Question 3

Who used the name element for any substance that cannot be broken down further, into a simpler substance. This definition can be extended to include the fact that each element is made up of only one kind of atom

Answer 3

Robert boyle

Question 4

Atom:

Answer 4

The smallest unit of an element which may or may not have an independent existence but always takes part in a chemical reaction is called atom.

Question 5

Molecules:

Answer 5

The smallest unit of a pure substance, which always exists independently and can retain physical and chemical properties of that substance is called a molecule.

Question 6

When two or more elements combine chemically to form a new substance, the new substance is called a ________. For example, cane sugar is made up of three elements carbon, hydrogen and oxygen. The chemical forumula of cane sugar is C₁₂H22 O11

Answer 6

compound

Question 7

A compound has properties that are different from those of the elements from which it is made

Answer 7

Common salt, also known as sodium chloride, is a compound. It is added to give taste to our food. It is a compound made up of a metal, sodium, that reacts violently with water and a poisonous non-metal, chlorine.

Question 8

Compounds of _________ are used in fertilizers,

______ compounds are of immense importance in the computer industry.

Compounds of _______ are used in our toothpastes as they strengthen our teeth.

Answer 8

1 phosphorous, nitrogen and potassium
2 Silicon
3 fluorine

Question 9

A _________ is an impure substance. It contains two or more kinds of elements or compounds or both physically mixed together in any ratio

Answer 9

mixture

Question 10

Element

Answer 10

Made up of only one kind of atom.

The smallest particle that retains all its properties is the atom,

Cannot be broken down into simpler substances

Question 11

Compound

Answer 11

Made up of more than one kind of atom.

The smallest particle that retains all its properties is the molecule.

Can be broken down into elements by chemical methods.

Question 12

Blood is not a pure substance… It is a mixture of various components such as

Answer 12

platelets, red and white blood corpuscles and plasma.

Question 13

Mixture

Answer 13

It contains two or more substances

The constituent may be present in any proportion.

They show the properties of their constituents.

The components may be separated easily by physical methods.

Question 14

Compound

Answer 14

It is a single substance

Theconstituents are present in definite proportions.

They do not show the properties of the constituent elements.

The constituents can only be separated by one or more chemical reactions.

Question 15

A mixture in which the components cannot be seen separately is called a

Answer 15

homogeneous mixture
every part of the mixture has the same properties

Question 16

homogeneous mixtures.

Answer 16

Tap water, milk, air, ice cream, sugar syrup, ink, steel, bronze and salt solution

Question 17

A mixture in which the components can be seen separately is called a

Answer 17

heterogeneous mixture..

It does not have a uniform composition and properties

Question 18

heterogeneous mixture.

Answer 18

Soil, a mixture of iodine and common salt, a mixture of sugar and sand, a mixture of oil and water, a mixture of sulphur and iron filings and a mixture of milk and cereals

Question 19

Certain solid substances when heated

when cooled give b

process is known

Iodine, camphor, a

EX Hong

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chloride and sand

covered with a pe

inverted funnel

sheet as shown in

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holes in the asbe

the inner sides of

impurities remain

More to Kno

The air freshner

slowly sublime

smell in the to

time. Moth bal

used to drive a

insects. These

Camphor, is a

change directly from solid to gaseous state household. It without attaining liquid state. The vapours when cooled give back the solid substance. This process is known as

Answer 19

sublimation

Question 20

Sublimation

Answer 20

Air freshener
Moth ball
Camphor

Question 21

Solid and solid
Heterogeneous mixture

Answer 21

Method of separation
Handpicking, sieving, winnowing, magnetic separation, sublimation.

Question 22

Heterogeneous mixture
Insoluble Solid and liquid

Answer 22

Method of separation
Sedimentation and decantation, loading, filtration, centrifugation

Question 23

Heterogeneous mixture
Two immiscible liquid

Answer 23

Decantation, separating funnel

Question 24

Homogeneous mixture
Soluble Solid and liquid

Answer 24

Method of separation
Evaporation, distillation, crystallisation

Question 25

Homogeneous mixture Two miscible liquid

Answer 25

Fractional distillation

Question 26

Homogeneous mixture Solution of two or more solids in a liquid

Answer 26

Method of separation Chromatography

Question 27

_______ is the process by which fine insoluble solids from a solid- liquid mixture can be separated in a machine called a centrifuge

Answer 27

Centrifugation

Question 28

Centrifugation used in

Answer 28

to separate cream from milk. In washing, machines, this principle is used to squeeze out water from wet clothes. Centrifugation is also used in pathological laboratories to separate blood cells from a blood sample.

Question 29

________ method works on the principle of difference in solubility of two immiscible liquids in a suitable solvent..

Answer 29

Solvent extraction

Question 30

mixture of water and oil can be separated using a

Answer 30

separating funnel Solvent extraction method

Question 31

________ method is used in pharmaceutical and petroleum industries

Answer 31

Solvent extraction

Question 32

______ is an old practice done for years. It is the main process in perfume development and it is also used to obtain dyes from various sources.

Answer 32

Solvent extraction

Question 33

________ is a process of obtaining pure liquid from a solution. It is actually a combination of evaporation and condensation i.e

Answer 33

Simple Distillation

Question 34

sea water in many countries is converted into drinking water by .

Answer 34

distillation

Question 35

Simple distillation method is also used to separate two liquids whose boiling points differ more than ____ K

Answer 35

25

Question 36

To separate two or more miscible liquids which do not differ much in their boiling points ______ is employed

Answer 36

fractional distillation (difference in boiling points is less than 25 )

Question 37

_______ is used in petrochemical industry to obtain different fractions of petroleum, to separate the different gases from air, to distil alcohols et

Answer 37

Fractional distillation

Question 38

__________ is the process in which the particles of a substance is concentrated only at the surface of another substance

Answer 38

Adsorption

Question 39

_______ is the process in which the substance is uniformly distributed throughout the bulk of another substance.

Answer 39

Absorption

Question 40

________ is also a separation technique. It is used to separate different components of a mixture based on their different solubilities in the same solvent

Answer 40

Chromatography

Question 41

____ method is used to separate the different coloured dyes in a sample of ink

Answer 41

Paper chromatography

Question 42

The black ink separates into its constituent dyes. As the solvent moves up the paper, the dyes are carried with it and begin to separate.

Answer 42

They separate because they have different solubility in the solvent and are adsorbed to different extents by the chromatography paper.

Question 43

The chromatogram shows that the black ink contains ____ dyes.

Answer 43

three

Question 44

_____ is a homogeneous mixture of two or more substances. In a solution, the component present in lesser amount by weight is called ____ and the component present in larger amount by weight is called ______.

Answer 44

solution solute solvent

Question 45

Based on the particle size of the substance, the solutions are divided into ______ types

Answer 45

three True solution Colloidal Suspension

Question 46

the case of sugar we get a clear solution and the particles never settle down. This mixture is called as

Answer 46

true solution.

Question 47

In the case of starch and water we get a cloudy mixture. This mixture is called as

Answer 47

colloidial solution

Question 48

In the case of wheat flour mixed with water we get a very turbid mixture and fine particles slowly settle down at the bottom after some time. This mixture is called as .

Answer 48

suspension

Question 49

What are the differences between True solutions, colloids and suspensions?

Answer 49

The major difference is the particle size. In fact interconversions of these mixtures are possible by varying the particle sizes by certain chemical and physical methods.

Question 50

A colloidal solution is a ______ system, consisting of the dispersed phase and the dispersion medium. Dispersed phase or the dispersion medium can be a solid, or liquid or gas

Answer 50

heterogeneous

Question 51

There are _____ different combinations possible in colloidal solution

Answer 51

8

Question 52

In colloidal solution , combination of gas in gas is not possible

Answer 52

Because gas in gas always forms a true solution

Question 53

Brownian movement of particles is due to the _______ of the particles by the molecules of dispersion medium

Answer 53

unbalanced bombardment Google*** The Brownian movement has a stirring effect which does not permit the particles to settle and thus, is responsible for the stability of sols.

Question 54

Tyndall (_______) observed that when a strong beam of light is focused on a colloidal solution the path of the beam becomes visible. This phenomenon is known as Tyndall 'effect and the illuminated path is called-

Answer 54

1869 Tyndall cone. This phenomenon is not observed in Fase of true solution

Question 55

The beam of light coming from headlights of vehicles is due to

Answer 55

Tyndall effect.

Question 56

Solid Solid

Answer 56

Solid sol Ex alloy, gems, coloured glass

Question 57

Solid - liquid

Answer 57

Sol Eg paint, ink, egg white

Question 58

Solid -gas

Answer 58

Aerosol Eg. Smoke ,dust

Question 59

Liquid - liquid

Answer 59

Emulsion Eg: milk , butter, oil in watter

Question 60

Liquid -solid

Answer 60

Gel Eg Curd cheese jelly

Question 61

Liquid -gas

Answer 61

Aerosol Eg Mist, fog, cloud

Question 62

Gas - solid

Answer 62

Solid foam Eg Cake bread

Question 63

Gas - liquid

Answer 63

Foam Eg Soap ,lather, aerated water

Question 64

An _______ is a colloid of two or more immiscible liquids where one liquid is dispersed in another liquid. This means one type of liquid particles get scattered in another liquid

Answer 64

emulsion

Question 65

In other words, an ______ is a special type of mixture made by combining two liquids that normally don't mix.

Answer 65

emulsion

Question 66

The word emulsion comes from the Latin word meaning

Answer 66

To milk (milk is one example of an emulsion of fat and water

Question 67

The process of turning a liquid mixture into an emulsion is called

Answer 67

emulsification

Question 68

________are some common examples of emulsions.

Answer 68

Milk, butter, cream, egg yolk, paints, cough syrups, facial creams, pesticides etc.

Question 69

The two liquids mixed can form different types of emulsions.

Answer 69

oil in water emulsion. Eg cream Water in oil emulsion. Eg butter

Question 70

When we mix a drop of ink in water we get a a) Heterogeneous Mixture b) Compound Homogeneous Mixture d) Suspension

Answer 70

Homogeneous mixture

Question 71

________ is essential to perform separation by solvent extraction method. a) Separating funnel b) filter paper b) centrifuge machine d) sieve

Answer 71

Separating funnel

Question 72

______ has the same properties throughout the sample a) Pure substance b) Mixture c) Colloid d) Suspension

Answer 72

Pure substance

Question 73

1. Oil and water are immiscible in each other. 2. A compound cannot be broken into simpler substances chemically. 3. Liquid-liquid colloids are called gels 4. Buttermilk is an example of heterogeneous mixture. 5. Aspirin is composed of 60% Carbon, 4.5% Hydrogen and 35.5% Oxygen by mass. False Aspirin is a mixture.

Answer 73

True False False True Flase

Question 74

A _________ mixture has no distinguishable boundary between its components.

Answer 74

Homogeneous

Question 75

An example of a substance that sublimes is

Answer 75

Naphthalene balls

Question 76

Alcohol can be separated from water by

Answer 76

Fractional distillation

Question 77

In petroleum refining, the method of separation used is

Answer 77

Fractional distillation

Question 78

Chromatography is based on the principle of

Answer 78

Adsorption

Question 79

A few drops of 'Dettol' when added to water the mixture turns turbid. Why?

Answer 79

because of emulsion.

Question 80

Name the apparatus that you will use to separate the components of mixtures containing two, i. miscible liquids, ii. immiscible liquids.

Answer 80

1) simple and fractional distillation 2 separating funnel