Chemistry

Is Matter Around Us Pure?

Question:

What are suspensions? Explain with an example.

Answer:

A suspension is a heterogeneous mixture in which very fine particles (about 10-5 m size) of solid are dispersed in any medium (liquid or gas). In suspension, the solute particles are visible to the naked eye, and remain suspended throughout the bulk of the medium. The Tyndall effect is observed in this mixture. Muddy pond water, smoke coming out of a chimney, chalk-water mixture, coarse lime particles in water are examples of suspension.
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Is Matter Around Us Pure?

Q 1.

Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass

Q 2.

What is a solution? What are the properties of a solution?

Q 3.

What are the properties of suspensions?

Q 4.

What are the differences and similarities between concentration and solubility?

Q 5.

What are the characteristics exhibited by a pure substance?

Q 6.

What are the reasons for separating the constituents of a mixture?

Q 7.

What factors affect the solubility of solvent and solute?

Q 8.

What are the physical states of dispersed phase and dispersion medium of a fog?

Q 9.

Name two properties of a substance to check its purity?

Q 10.

What are suspensions? Explain with an example.

Q 11.

What is meant by a pure substance?

Q 12.

To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293K. Find its concentration at this temperature.

Q 13.

State the differences between compounds and mixtures.

Q 14.

How crystallization is better than evaporation?

Q 15.

Name the elements are in liquid state at room temperature.

Q 16.

Why air is a mixture not a compound? Give reasons.

Q 17.

What are the advantages of preparing solutions?

Q 18.

Based on the type of solvent, how solutions are classified?

Q 19.

Define mixture.

Q 20.

21.5 g of sodium chloride dissolves in 60 g of water at 25°C. Calculate the solut water at that temperature.

Q 21.

Based on the amount of solute in the given solution, how solutions are classified?

Q 22.

Fill in the following blanks :
(a)Milk is a.........solution but vinegar is a.......solution.
(b)A colloid is a........mixture and its components can be separated by the technique known as........

Q 23.

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

Q 24.

A 5 per cent sugar solution means that:
(a)5 g of sugar is dissolved in 95 g of water.
(b)5 g of sugar is dissolved in 100 g of water.
Choose the correct answer.

Q 25.

Explain what happens when a beam of light is passed through a colloidal solution.

Q 26.

Name the process by which the various gases of the air are separated.

Q 27.

Name the property of any one of the components which can be used for separating the following mixture : Salt and Camphor

Q 28.

What are the kinds of mixture?

Q 29.

List the points of differences between homogeneous and heterogeneous mixtures.

Q 30.

What are the physical states of dispersed phase and dispersion medium of a cloud?

Q 31.

What are the various methods to express concentration of a solution?

Q 32.

Why solutions do not exhibit Tyndall effect?

Q 33.

Give examples of liquids that are
(i) completely miscible
(ii) partially miscible
(iii) practically immiscible

Q 34.

Which of the following is a mixture ?Salt, Air, Water, Alum, Sugar

Q 35.

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

Q 36.

Which of the following is a sol ?
Shaving cream,
Milk,
Fog,
Soap solution,
Hairspray

Q 37.

How will you distinguish a colloid from a solution ?

Q 38.

Name the process you would use to separate a mixture of two miscible liquids (like acetone and water).

Q 39.

Name one pair of substances whose mixture can be separated completely by distillation.

Q 40.

(a) Name the process by which common salt is obtained from sea-water.
(b) Name the process by which common salt is purified.

Q 41.

What are elements?

Q 42.

Why do fish go in deep waters during day light?

Q 43.

What are aqueous solutions?

Q 44.

How are sol, solution and suspension different from each other?

Q 45.

What do you mean by strength of the solution?

Q 46.

Describe sieving method.

Q 47.

How many elements are there which are in gaseous state at room temperature?

Q 48.

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

Q 49.

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

Q 50.

Classify the following into elements and compounds :
(i)H2O
(II) He
(III) Cl2
(iv) CO
(v)Co