CLASS VI-WORKSHEET

Chapter5: Separation of Substances

I.Multiple Choice Questions carrying one mark each –

(1)A liquid that is immiscible and two times heavier than water is mixed in it. The two liquids

can be separated by:
(a) separating funnel	(b) evaporation
(c) filtration	(d) distillation

(2)Vinegar is a mixture of acetic acid and water, it is a:

(a)homogeneous liquid in liquid mixture

(b)homogeneous liquid gas mixture

(c)hetrogeneous liquid in liquid mixture

(d)none of these

(3)Which method of separation will be used to separate iron fillings from sand?

(a) magnetic separation	(b) sieving
(c) hand picking	(d) all of these

(4)Sarita wants to separate beads of different sizes. The easiest way to separate them would be:

(a) hand picking (b) sieving (c) magnetic separation

(d) all of these

(5)A mixture contains particles of two solids of almost the same size but different weight (solid B is light, while solid A is heavy).They can be separated by:

(a) winnowing	(b) sieving
(c) filtration	(d) handpicking

2. Match the following carrying one mark each:

	(1)	Sugar		(a) mixture
	(2)	Vinegar		(b) sieving
	(3)	Mustard seeds and suji		(c) handpicking
(4) Pebbles from rice			(d) filtration
(5) Tea leaves from tea			(e) pure substance

3.Write True (T) or False (F) carrying one mark each:

(a)Soil is a mixture.

(b)Husk from grain can be separated by sieving.

(c) iron fillings and sulphur powder are mixed, a homogeneous mixture is obtained.

4.Fill in the Blanks carrying one mark each:

(a)A…………… does not have a definite melting and boiling point.

(b)Stone,wood,fruits are examples of …………………. occurring materials.

(c)…………………. Is removed from sea water,to make it fit for drinking.

(d).The clear liquid obtained after filtration is called ………………………. .

5.Answer in one line only carrying two marks each:

(a)Define sieving.

(b)Define winnowing.

(c)Define decantation.

(d)What is mixture?

(e)What is a pure substance?

(f)Define filtration.

(g)How can pieces of iron scrap be separated from garbage dumps?

(h)What kind of mixture can be separated by handpicking?

(i)Define sedimentation.

(j)Write three properties of mixture.

(k)How are homogeneous mixtures different from heterogeneous mixtures?

(l)Write the methods you will use to separate and mixture of iron filling, common salt and Sand.

(m)Write the methods you would use to separate:

(i) Coconut oil, water &salt

(ii) Chalk powder, marbles &water

(n)Which are the two most common filters used at homes to purify water for drinking?

(o)Meenu accidently drops tea leaves into a jar containing salt. Explain the process she should use to separate them so that both could be used.

6.Answer in two or three lines only carrying three marks each:

(a)List three properties of pure substances.

(b)Write three needs for separating of constituents of a mixture.

(c)Define loading.

(d)Why does the air become clean and fresh after it rains?

(e)Explain how is salt obtained from sea water.

(f)Give two reasons why components of a mixture need to be separated.

(g)Describe a simple activity to explain the process of filtration.

(h)Explain the step how you will separate the mixture of salt, sand and water?

Name the methods involved at each step.

(i)Give reasons for the following: (i) Salt and sand cannot be separated by winnowing.

(j)Describe in your words how will you prepare a saturated solution of sugar in water.

Chapter6: Changes Around Us

I. Multiple Choice Questions carrying one mark each–

(1) A baby grows into an adult,it is an example of a:

(a) slow and irreversible change	(b) fast and irreversible change
(c) slow and reversible change	(d) fast and reversible change

(2)Which of the following is a feature of a physical change?

(a)It is reversible

(b)it is a permanent change

(c)a new substance is formed

(d)all of these

(3)The bursting of a cracker is a:

(a) fast change		(b) irreversible change
(c) reversible change		(d) both a & b
(4) Overcooking of food is a/an:
(a) undesirable change		(b) desirable change (c) physical change	(d) all of these
(5) A forest fire is a an:
(a) physical change		(b) undesirable change
(c) desirable change		(d) all of these
2. Match the following carrying one mark each:
(1)	Slow change	(a) cooking of food
(2)	Fast change	(b) seed to a tree
(3)	Desirable change	(c) burning of paper
(4)	Undesirable change	(d) water to ice
(5) Physical change		(e) over ripening of a fruit

3. Write True (T) or False (F) carrying one mark each:

(a)A new substance is formed during a chemical change.

(b)A physical change is a temporary change.

(c)Sublimation is an irreversible change.

(d)Breaking of glass is a man‐made irreversible change.

(e)Solvent is the component that dissolves in a liquid.

4.Fill in the Blanks carrying one mark each:

(a)…………… is a homogeneous mixture of a solute and solvent.

(b)In a sugar solution,…………….. is the solute and …………….is the solvent.

(c)…………………. Is the change of a state of a liquid to a solid.

(d)The solubility of a solvent ………………….. on heating.

(e)Metals……………………. on cooling and ………………… on heating .

5.Answer in one line only carrying two marks each:

(a)Give an example to show how force changes the shape of a material.

(b)‘Changes involve interaction’. Give an example to support this statement.

(c)    (c)What is a solvent?

Classify the following changes in at least three ways each:

(i) Growth of a baby

(ii) Drying of clothes (iii) Rusting of iron.

(g)Why is gap left between two rails?

(h)Define solubility.

(i)Why do telephone and electric wires sag in summers and become tight in winters?

(j)Describe a simple activity to show that melting of wax is a reversible change.

(k)Mention two changes that will take place when water is heated in a pan.

(l)What products are obtained when an incense stick is burned? Can this change be reversed? Explain.

(m)Give two examples of changes that occur due to mixing of substances.

(n)Give three examples of changes that take place in nature on their own.

(o)During evaporation water changes into vapour form. What is the reverse of this process Called? Define it.

6.Answer in two or three lines only carrying three marks each:

(a)List three properties of a physical change.

(b)Why are tools often heated before fixing wooden handles?

(c)How does a reversible change differ from an irreversible change?

(d)List three properties of a chemical change.

(f)Give an example of a change that takes place even when the two materials are not in contact.

(g)Explain how the states of water can be inter changed.

(h)Give two examples to explain how change of state due to pressure can be brought about.

(i)A sculptor makes a bronze statue. However he is not satisfied with it. Can he reverse the process? How?

(j)Give examples and explain the difference between changes that can be reversed or cannot be reversed.