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.
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 are aqueous solutions?
Q 13.
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 14.
Name the technique to separate
(i) butter from curd
(ii) salt from sea-water
(iii) camphor from salt
Q 15.
What is a solution? What are the properties of a solution?
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 the physical states of dispersed phase and dispersion medium of a cloud?
Q 22.
What are the reasons for separating the constituents of a mixture?
Q 23.
Name a non-metal which is a good conductor of electricity.
Q 24.
What are pure substances ? Give two examples of pure substances.
Q 25.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Q 26.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Q 27.
What is meant by a pure substance?
Q 28.
On the basis of composition, how matter is classified?
Q 29.
What are non-aqueous solutions?
Q 30.
What are suspensions? Explain with an example.
Q 31.
Explain with an example what is a colloid?
Q 32.
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 33.
What are different ways to separate solid mixtures?
Q 34.
Define Brownian movement in colloids.
Q 35.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 36.
(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 37.
What is the difference between solutions and colloids ?
Q 38.
Which of the following will show Tyndall effect ? Why ?
(a) Salt solution
(b) Starch solution
(c)Milk
Q 39.
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
Q 40.
Name one pair of substances whose mixture can be separated by fractional distillation.
Q 41.
Name one pair of substances whose mixture can be separated completely by distillation.
Q 42.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 43.
Name the process which is used in milk dairies to separate cream from milk.
Q 44.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
Q 45.
What are the kinds of mixture?
Q 46.
How elements are further classified?
Q 47.
State the differences between compounds and mixtures.
Q 48.
Why do fish go in deep waters during day light?
Q 49.
Based on the type of solvent, how solutions are classified?
Q 50.
Based on the amount of solute in the given solution, how solutions are classified?
