Question:
What is Chromatography?
Answer:
Chromatography is a technique used to separate those solutes of a mixture which are soluble in the same solvent. It works on the principle of adsorption. It is used to separate the coloured components (dyes) in black ink.
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.
What are the physical states of dispersed phase and dispersion medium of a fog?
Q 4.
Choose one term from the following which includes the other three :
aerosol,
emulsion,
colloid,
sol
Q 5.
Name the property of any one of the components which can be used for separating the following mixture : Salt and Camphor
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.
What is a solution? What are the properties of a solution?
Q 15.
What are the various methods to express concentration of a solution?
Q 16.
Name the technique to separate
(i) butter from curd
(ii) salt from sea-water
(iii) camphor from salt
Q 17.
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
Q 18.
What are the characteristics of mixture?
Q 19.
What is an unsaturated solution?
Q 20.
What are the physical states of dispersed phase and dispersion medium of a cloud?
Q 21.
What are the reasons for separating the constituents of a mixture?
Q 22.
How crystallization is better than evaporation?
Q 23.
Name a non-metal which is a good conductor of electricity.
Q 24.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Q 25.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Q 26.
What is meant by a pure substance?
Q 27.
On the basis of composition, how matter is classified?
Q 28.
What are non-aqueous solutions?
Q 29.
What are suspensions? Explain with an example.
Q 30.
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 31.
What are different ways to separate solid mixtures?
Q 32.
Define Brownian movement in colloids.
Q 33.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 34.
What are pure substances ? Give two examples of pure substances.
Q 35.
(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 36.
Which of the following will show Tyndall effect ? Why ?
(a) Salt solution
(b) Starch solution
(c)Milk
Q 37.
Name one pair of substances whose mixture can be separated completely by distillation.
Q 38.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 39.
Name the process which is used in milk dairies to separate cream from milk.
Q 40.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
Q 41.
What are the kinds of mixture?
Q 42.
State the differences between compounds and mixtures.
Q 43.
Why do fish go in deep waters during day light?
Q 44.
Based on the type of solvent, how solutions are classified?
Q 45.
Based on the amount of solute in the given solution, how solutions are classified?
Q 46.
What are the advantages of preparing solutions?
Q 47.
Explain with an example what is a colloid?
Q 48.
Name the elements are in liquid state at room temperature.
Q 49.
Who used the term 'element' first time?
Q 50.
Who gave the first explanatory definition of 'element'?
