Lakhmir Singh Solutions - Chemistry - Class 9 solutions for Chapter 2 Is Matter Around Us Pure?

State whether the following statement is true or false:

Milk is a pure substance.

Name three mixtures found in nature.

Name a non-metal which is a good conductor of electricity.

Which of the following is a mixture?

Salt, Air, Water, Alum, Sugar

Name one metal and one non-metal which exist as liquids at room temperature.

Name a liquid which can be classified as a pure substance and conducts electricity.

Which type of elements, metal or non- metals, show the property of brittleness?

Name the property:

(a) Which allows metals to be hammered into thin sheets?

What is meant by saying that non-metals are brittle ?

What is meant by saying that metals are malleable and ductile?

What is meant by saying that metals are lustrous ?

What is meant by saying that metals are sonorous ?

Name one solid, one liquid and gaseous non – metal.

What is the general name of the materials which contain at least two pure substances and show the properties of the constituents?

“The properties of the product are different from those of the constituents”. State whether this statement best describes an element, a compound or a mixture.

Name one element, one compound and one mixture.

What is the major difference between a solution and an ordinary mixture?

What name is given to those elements which are neither good conductors of electricity like copper nor insulators like sulphur?

Fill in the following blanks with suitable words:

(a) An element is made up of only one kind of _________.

(b) Brine is a _______ whereas alcohol is a _________.

(c) Brass is an alloy which is considered a _______ .

(e) The elements which are sonorous are called ________ .

(d) The three important metalloids are ______, _______ and__ .

Classify the following into elements and compounds:

(i) H2O

Classify the following into elements and compounds:

(ii) He

Classify the following into elements and compounds:

(iii) Cl₂

Classify the following into elements and compounds:

(iv) CO

Classify the following into elements and compounds:

(v) Co

Classify the following as elements or compound:

Iron, Iron sulphide, Sulphur, Chalk, Washing soda, Sodium, Carbon, Urea

What elements do the following compounds contain?

Sugar, Common salt

What are pure substances? Give two examples of pure substances.

What are the two types of pure substances? Give one example of each type.

Which of the following are ‘pure substances’?

Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air

Give two reasons for supposing that water is a compound and not a mixture.

What is the other name for impure substances? Give two examples of impure substances.

Name two solid, liquid and two gaseous elements at the room temperature.

Define a compound. Give two points of evidence to show that sodium chloride is a compound.

State three reasons why you think air is a mixture and water is a compound.

State any two properties for believing that aluminium is a metal.

Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.

What are the three groups into which all the elements can be divided? Name two elements belonging to each group.

Is air a mixture or a compound? Give three reasons for your answer.

Which of the following substances are elements?

Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine

State two physical properties on the basis of which metals can be distinguished from non-metals.

Compare the properties of metals and non- metals with respect to (i) malleability (ii) ductility, and (iii) electrical conductivity.

Give reason why:

(a)Copper metal is used for making electric wires.

Give reason why:

(b)Graphite is used for making electrode in a dry cell.

How would you confirm that a colourless liquid given to you is pure water?

Choose the solutions from among the following mixtures:

Soil, Sea-water, Air, Coal, Soda-water

Define a mixture. Give two points of evidence to show that sugar solution is a mixture.

State two reasons for supposing that brass is a mixture and not a compound.

State one property in which a solution of sugar in water resembles a mixture of sugar and sand, and one property in which it differs from it.

List five characteristics by which compounds can be distinguished from mixtures.

Explain why, a solution of salt in water is considered a mixture and not a compound.

You are given two liquids, one a solution and the other a compound. How will you distinguish the solution from the compound?

Name a non-metal:

(a) Which is lustrous?

Name a non-metal:

(b) Which is required for combustion?

Name a non-metal:

(c) Whose one of the allotropic forms is a good conductor of electricity. Name the allotrope.

Name a non-metal:

(d) Other than carbon which shows allotropy

Name a non-metal:

(e) Which is known to form the largest number of compounds?

Name a metal:

(a)Which can be easily cut with a knife

Name a metal:

(b)Which forms amalgams

Which of the following is not an element?

(a) Graphite

(b) Germanium

(c) Silica

(d) Silicon

Name a metal:

(c)Which has no fixed shape

Name a metal:

(d)Which has a low melting point

Name a metal:

(e) Which is yellow in colour is yellow in colour

Which of the following are not compounds?

Chlorine gas, potassium chloride, Iron powder, Iron sulphide, Aluminium foil, Iodine vapour, Graphite, Carbon monoxide, Sulphur powder, Diamond

(b) Classify the following materials as homogeneous mixtures and heterogeneous mixtures.

Soda-water, Wood, Air, Soil, Vinegar, Alcohol and water mixture, Petrol and water mixture, Chalk and water mixture, Sugar and water mixture, Copper sulphate solution.

(a) What is meant by (i) elements (ii) compound, and (iii) mixtures? Write down the names of two elements, two compounds and two mixtures.

(b) Classify the flowing into elements , compounds and mixtures:

Marble, Air, Gold, Brass, Sand, Diamond, Graphite, Petroleum, Common salt, Sea-water, Chalk

(a) What are (i) metals (ii) non-metals, and (iii) metalloids? Give two examples each of metal, non-metals and metalloids.

(b) Classify the following into metals, non-metals and metalloids:

Silicon, Mercury, Diamond, Sulphur, Iodine, Germanium, Sodium, Carbon, Magnesium, Copper, Boron, Helium

(a) What is a mixture? Give two example of mixtures.

(b) What is meant by (i) homogeneous mixtures, and (ii) Heterogeneous mixtures? Give two examples of homogeneous mixtures and two of heterogenous mixtures.

(c) What is the other name of homogenous mixtures?

(a)What are the three general classes of matter? Give one example of each type.

(b) Draw a flow chart for the schematic representation of different types of matter.

Which of the following are compounds?

(i) CO (ii) No (iii) NO (iv) Co

(a) (i) and (ii)

(b) (ii) and (iii)

(c) (i) and (iii)

(d) (ii) and (iv)

One of the following substances is neither good conductor of electricity nor an insulator. This substance is:

(a) Chromium

(b) Germanium

(c) Gallium

(d) Potassium

. Which of the following is not a mixture?

(a) Kerosene

(b) Air

(c) Alcohol

(d) Petrol

The element which is not common between the compounds called baking soda and soda ash is:

(a) Sodium

(b) Hydrogen

(c) Oxygen

(d) Carbon

"Is malleable and ductile” best decribes:

(a) A solution

(b) A metal

(c) A compound

(d) A non-metal

The elements which normally exist in the liquid state are:

(a) Bromine and Iodine

(b) Mercury and chlorine

(c) Iodine and mercury

(d) Bromine and mercury

Which one of the following is not a metalloid?

(a) Boron

(b) Silicon

(c) Gallium

(d) Germanium

The property/properties which enable copper metal to be used for making electric wires is/are:

(a) Copper metal is malleable and ductile

(b) Copper metal is good conductor of electricity

(c) Copper metal is ductile and has low electrical resistance

(d) Copper metal is sonorous and an excellent conductor of electricity

On the basis of composition of matter, milk is considered to be:

(a) A pure substance

(b) An impure substances

(c) An element

(d) A compound

Which of the following statement are true for pure substances?

(i) Pure substances contain only one kind of particles

(ii) Pure substances may be compounds or mixtures

(iii) Pure substances have the same composition throughout

(iv) Pure substances can be exemplified by all elements other than nickel

(a) (i) and (ii)

(b) (i) and (iii)

(c) (iii) and (iv)

(d) (ii) and (iii)

Two chemical substance X and Y combine together to form a product P which contains X and Y

X + Y → P

X and Y cannot be broken down into simpler substance by simple chemical reactions. Which of the following statements concerning X, Y and P are correct?

(i) P is a compound

(ii) X and Y are compounds

(iii) X and Y are elements

(iv) P has a fixed composition

(a) (i), (ii) and (iii)

(b) (i), (ii) and (iv)

(c) (ii), (iii) and (iv)

(d) (i), (iii) and (iv)

Which of the following does not have a fixed melting point/boiling point?

(a) Gold

(b) Ethanol

(c) Air

(d) Oxygen

When a mixture of iron powder and sulphur powder is heated strongly to form iron sulphide, then heat energy is:

(a) Released

(b) First absorbed and then released

(c) Absorbed

(d) Neither absorbed nor released

a) State the main points of difference between homogeneous and heterogeneous mixtures.

Name the property:

(b) Which enables metals to be drawn into wires.

Name a metal which is soft and a non- metal which is hard.

Lakhmir singh solutions chemistry class 9 Solutions for Chapter 2 is matter around us pure