Question:
What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?
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.
What are the properties of a colloid?
Q 3.
Name the property of any one of the components which can be used for separating the following mixture : Salt and Camphor
Q 4.
What are the physical states of dispersed phase and dispersion medium of a fog?
Q 5.
Choose one term from the following which includes the other three :
aerosol,
emulsion,
colloid,
sol
Q 6.
What is saturated solution? Explain with an example.
Q 7.
Classify the following as physical or chemical changes :
(i) Cooking of food
Q 8.
Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.
Q 9.
Name one pair of liquids which can be separated by using a separating funnel.
Q 10.
What is meant by solute and solvent?
Q 11.
Name a metal which is soft and a non-metal which is hard.
Q 12.
What is a solution? What are the properties of a solution?
Q 13.
What are aqueous solutions?
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 the technique to separate
(i) butter from curd
(ii) salt from sea-water
(iii) camphor from salt
Q 16.
What are the various methods to express concentration of a solution?
Q 17.
How crystallization is better than evaporation?
Q 18.
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
Q 19.
What are the characteristics of mixture?
Q 20.
What is an unsaturated solution?
Q 21.
What are suspensions? Explain with an example.
Q 22.
What are the physical states of dispersed phase and dispersion medium of a cloud?
Q 23.
What are the reasons for separating the constituents of a mixture?
Q 24.
Name a non-metal which is a good conductor of electricity.
Q 25.
What are pure substances ? Give two examples of pure substances.
Q 26.
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
Q 27.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Q 28.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Q 29.
What is meant by a pure substance?
Q 30.
On the basis of composition, how matter is classified?
Q 31.
Why do fish go in deep waters during day light?
Q 32.
What are non-aqueous solutions?
Q 33.
Explain with an example what is a colloid?
Q 34.
A solution contains 40 mL of ethyl alcohol mixed with 100mL of water. What is the concentration of the solution in terms of volume by volume percentage?
Q 35.
What are different ways to separate solid mixtures?
Q 36.
Define Brownian movement in colloids.
Q 37.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 38.
Why solutions do not exhibit Tyndall effect?
Q 39.
What is the general name of the materials which contain at least two pure substances and show the properties of their constituents ?
Q 40.
(a) What is meant by (i) elements (ii) compounds, and (iii) mixtures ? Write down the names of two elements,two compounds and two mixtures.
(b) Classify the following into elements,
compounds and mixtures :
Marble,
Air,
Gold,
Brass,
Sand,
Diamond,
Graphite,
Petroleum,
Common salt,
Sea-water,
Chalk
Q 41.
What is the difference between solutions and colloids ?
Q 42.
Which of the following will show Tyndall effect ? Why ?
(a) Salt solution
(b) Starch solution
(c)Milk
Q 43.
Name one pair of substances whose mixture can be separated by fractional distillation.
Q 44.
Name one pair of substances whose mixture can be separated completely by distillation.
Q 45.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 46.
Name the process which is used in milk dairies to separate cream from milk.
Q 47.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
Q 48.
What are the characteristics exhibited by a pure substance?
Q 50.
What are the kinds of mixture?
