Question:
What are the advantages of preparing solutions?
Answer:
In a solution, solute and solvent may be present in the form of ions or molecules or both. Solutions are obtained for the following reasons:
- To carry out reactions. For a reaction to take place, reactant molecules must come close together. In solutions, reactions take place faster because reactants are in ionic or molecular form an dare close to each other.
- As dissolving medium like medicines. Certain medicines can only be administered to patients in solution form only. e.g. saline glucouse solution is given to patients suffering from dehydration.
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.
Classify the following as physical or chemical changes :
(i) Cooking of food
Q 3.
Name the property :
(a) which allows metals to be hammered into thin sheets.
(b)
Q 4.
Name one pair of liquids which can be separated by using a separating funnel.
Q 5.
What is meant by saying that metals are malleable and ductile ?
Q 6.
How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
Q 7.
Name the property of any one of the components which can be used for separating the following mixture : Salt and Camphor
Q 8.
What is saturated solution? Explain with an example.
Q 9.
Calculate the mass of glucouse and mass of water required to make 200g of 25% solution of glucouse.
Q 10.
Define Brownian movement in colloids.
Q 11.
What is an emulsion? Give examples
Q 12.
Give two reasons for supposing that water is a compound and not a mixture.
Q 13.
Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.
Q 14.
What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?
Q 15.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 16.
What are non-aqueous solutions?
Q 17.
What is an unsaturated solution?
Q 18.
Which of the following is a mixture ?Salt, Air, Water, Alum, Sugar
Q 19.
Name a non-metal which is a good conductor of electricity.
Q 20.
Name one pair of substances whose mixture can be separated by fractional distillation.
Q 21.
On the basis of composition, how matter is classified?
Q 22.
What are different categories of pure substance?
Q 23.
What is meant by solute and solvent?
Q 24.
Explain with an example what is a colloid?
Q 25.
What are the reasons for separating the constituents of a mixture?
Q 26.
State whether the following statement is true or false : Milk is a pure substance.
Q 27.
What are pure substances ? Give two examples of pure substances.
Q 28.
(a) What is meant by a solution ? Give two examples of solutions.
(b)What is a suspension ? Give two examples of suspensions.
(c)
Q 29.
How are sol, solution and suspension different from each other?
Q 30.
What are different ways to separate solid mixtures?
Q 31.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 32.
Which of the following will show Tyndall effect ? Why ?
(a) Salt solution
(b) Starch solution
(c)Milk
Q 33.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Q 34.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Q 35.
What are the kinds of mixture?
Q 36.
State the differences between compounds and mixtures.
Q 37.
What is a solution? What are the properties of a solution?
Q 38.
What are suspensions? Explain with an example.
Q 39.
What do you mean by strength of the solution?
Q 40.
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 41.
Name the technique to separate
(i) butter from curd
(ii) salt from sea-water
(iii) camphor from salt
Q 42.
Give examples of liquids that are
(i) completely miscible
(ii) partially miscible
(iii) practically immiscible
Q 43.
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
Q 44.
Name any two solid substances whose mixture can be separated by sublimation.
Q 45.
Name one pair of substances whose mixture can be separated completely by distillation.
Q 46.
How will you separate a mixture of chalk powder and water ?
Q 47.
What are the constituents of brass?
Q 48.
What is supersaturated solution?
Q 49.
What are the properties of suspensions?
Q 50.
What are the physical states of dispersed phase and dispersion medium of a fog?
