Question:
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
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.
Choose one term from the following which includes the other three :
aerosol,
emulsion,
colloid,
sol
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.
Name any two solid substances whose mixture can be separated by sublimation.
Q 6.
What are the properties of a colloid?
Q 7.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Q 8.
What are aqueous solutions?
Q 9.
What is saturated solution? Explain with an example.
Q 10.
What are the physical states of dispersed phase and dispersion medium of a cloud?
Q 11.
What is a solution? What are the properties of a solution?
Q 12.
Classify the following as physical or chemical changes :
(i) Cooking of food
Q 13.
What is meant by solute and solvent?
Q 14.
What are suspensions? Explain with an example.
Q 15.
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 16.
What are pure substances ? Give two examples of pure substances.
Q 17.
Name one pair of substances whose mixture can be separated completely by distillation.
Q 19.
When we open the cap of a cola drink (or any carbonated beverage), why does excess of bubbles come out?
Q 20.
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 21.
How crystallization is better than evaporation?
Q 22.
Define Brownian movement in colloids.
Q 23.
Name the following :
(a) a lustrous liquid metal.
(b) a liquid non-metal
(c) a metal which can be cut with a knife
(d) a non-metal which is good conductor of electricity.
(e) an element which melts when kept on the palm.
(f) the best conductor of heat.
Q 24.
What is an emulsion? Give examples
Q 25.
Name one pair of liquids which can be separated by using a separating funnel.
Q 26.
What are the reasons for separating the constituents of a mixture?
Q 27.
What principle is applied in centrifugation? Give examples where this method is applied to separate mixtures.
Q 28.
What is the general name of the materials which contain at least two pure substances and show the properties of their constituents ?
Q 29.
Give two reasons for supposing that water is a compound and not a mixture.
Q 30.
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 31.
Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.
Q 32.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 33.
(a) Name the process by which common salt is obtained from sea-water.
(b) Name the process by which common salt is purified.
Q 34.
On the basis of composition, how matter is classified?
Q 35.
What are the constituents of brass?
Q 36.
State the differences between compounds and mixtures.
Q 37.
What are non-aqueous solutions?
Q 38.
Why air is a mixture not a compound? Give reasons.
Q 39.
What is an unsaturated solution?
Q 40.
What is Chromatography?
Q 41.
A good method to separate alum (phitkari) from impure samples is
(a) Filtration
(b) Sedimentaion
(c) Crystallization
(d) Sublimation
Q 42.
How many elements are there which are in gaseous state at room temperature?
Q 43.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 44.
In beaker A, sugar cubes are dissolved into water while in beaker B, crushed cubes are taken. In which beaker the rate of dissolution is faster?
Q 45.
Name a metal which is soft and a non-metal which is hard.
Q 46.
(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 47.
Which of the following will show Tyndall effect ? Why ?
(a) Salt solution
(b) Starch solution
(c)Milk
Q 48.
(a) What is meant by a solution ? Give two examples of solutions.
(b)What is a suspension ? Give two examples of suspensions.
(c)
Q 49.
Name one pair of substances whose mixture can be separated by fractional distillation.
Q 50.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
