Chemistry

Is Matter Around Us Pure?

Question:

What are the differences and similarities between concentration and solubility?

Answer:

  1. Concentration is amount of solute dissolved in a unit quantity (mass or volume) of a solution. While solubility is the maximum amount of the solute that can be dissolved in a given amount of the solvent.
  2. Concentration is expressed as percent by weight or volume, mole fraction, molarity etc. Solubility is the ability of a solute to dissolve in a solvent at given temperature and pressure. It is expressed as grams/litre or moles/litre.
  3. Based on concentration, a solution can be saturated, unsaturated or supersaturated. Based on solubility, the solutes are soluble or insoluble, miscible or immiscible.
  4. (Similarity) Both depends on temperature.
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Is Matter Around Us Pure?

Q 1.

What is the general name of the process by which tea-leaves are separated from prepared tea ?

Q 2.

How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?

Q 3.

Classify the following as physical or chemical changes :
(i) Cooking of food

Q 4.

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

Q 5.

Name one pair of liquids which can be separated by using a separating funnel.

Q 6.

Define Brownian movement in colloids.

Q 7.

Calculate the mass of glucouse and mass of water required to make 200g of 25% solution of glucouse.

Q 8.

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

Q 9.

What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?

Q 10.

What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?

Q 11.

Name the property of one of the constituents which can be used to separate a mixture of salt and iodine

Q 12.

What are non-aqueous solutions?

Q 13.

What is saturated solution? Explain with an example.

Q 14.

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 15.

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

Q 16.

Name the property :
(a) which allows metals to be hammered into thin sheets.
(b)

Q 17.

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

Q 18.

Name the process which can be used to separate a mixture of salt solution and sand.

Q 19.

Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?

Q 20.

State the differences between compounds and mixtures.

Q 21.

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

Q 22.

Which of the two will scatter light: soap solution or sugar solution ? Why ?

Q 23.

How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?

Q 24.

Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.

Q 25.

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

Q 26.

Name the source from which nitrogen and oxygen are obtained on a large scale.

Q 27.

How is cream separated from milk ?

Q 28.

What are different categories of pure substance?

Q 29.

Define mixture.

Q 30.

What is an unsaturated solution?

Q 31.

What are different ways to separate solid mixtures?

Q 32.

Who used the term 'element' first time?

Q 33.

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

Q 34.

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

Q 35.

State whether the following statement is true or false : Milk is a pure substance.

Q 36.

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

Q 37.

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

Q 38.

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

Q 39.

Name the process you would use to separate a mixture of anthracene and copper sulphate ?

Q 40.

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

Q 41.

Name any two solid substances whose mixture can be separated by sublimation.

Q 42.

Name the process which is used in milk dairies to separate cream from milk.

Q 43.

What are the characteristics of mixture?

Q 44.

Explain with an example what is a colloid?

Q 45.

How will you separate a mixture of chalk powder and water ?

Q 46.

State one application of centrifugation.

Q 47.

How will you separate iron pins from sand ?

Q 48.

What are the kinds of mixture?

Q 49.

List the points of differences between homogeneous and heterogeneous mixtures.

Q 50.

What are elements?