Question:
What is a solution? What are the properties of a solution?
Answer:
A homogeneous mixture of two or more substances is called a solution. Properties of a solution
- A solution is a homogeneous mixture i.e. the solute and solvent molecules cannot be distinguished even under a microscope.
- The particles of a solution are smaller than 1 nm in diameter. So, they cannot be seen by naked eyes.
- A true solution is clear and transparent ( A few may be coloured one but clear. e.g. Copper Sulphate solution)
- Because of very small particle size, they do not scatter a beam of light passing through the solution. So, the path of light is not visible in a solution.
- The solute particles cannot be separated from the mixture by the process of filtration.
- The solute particles do not settle down when left undisturbed, that is, a solution is stable.
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.
How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
Q 3.
Classify the following as physical or chemical changes :
(i) Cooking of food
Q 4.
Name one pair of substances whose mixture can be separated by fractional distillation.
Q 5.
Name one pair of liquids which can be separated by using a separating funnel.
Q 6.
Calculate the mass of glucouse and mass of water required to make 200g of 25% solution of glucouse.
Q 7.
Define Brownian movement in colloids.
Q 8.
What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?
Q 9.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Q 10.
What is saturated solution? Explain with an example.
Q 11.
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 12.
Give two reasons for supposing that water is a compound and not a mixture.
Q 13.
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
Q 14.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 15.
State the differences between compounds and mixtures.
Q 16.
What are non-aqueous solutions?
Q 17.
What is an unsaturated solution?
Q 18.
How are sol, solution and suspension different from each other?
Q 19.
Name a non-metal which is a good conductor of electricity.
Q 20.
Name the property :
(a) which allows metals to be hammered into thin sheets.
(b)
Q 21.
What is meant by saying that metals are malleable and ductile ?
Q 22.
Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.
Q 23.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
Q 24.
What are different categories of pure substance?
Q 26.
Give examples of liquids that are
(i) completely miscible
(ii) partially miscible
(iii) practically immiscible
Q 27.
What is the general name of the materials which contain at least two pure substances and show the properties of their constituents ?
Q 28.
Which of the two will scatter light: soap solution or sugar solution ? Why ?
Q 29.
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
Q 30.
Name the property of any one of the components which can be used for separating the following mixture : Salt and Camphor
Q 31.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Q 32.
Name the process which is used in milk dairies to separate cream from milk.
Q 33.
How is cream separated from milk ?
Q 34.
Explain with an example what is a colloid?
Q 35.
What are different ways to separate solid mixtures?
Q 36.
Who used the term 'element' first time?
Q 37.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 38.
State whether the following statement is true or false : Milk is a pure substance.
Q 39.
Which of the following is a mixture ?Salt, Air, Water, Alum, Sugar
Q 40.
Classify the following into elements and compounds :
(i)
Q 41.
Name the process you would use to separate a mixture of anthracene and copper sulphate ?
Q 42.
Name the process by which the various gases of the air are separated.
Q 43.
Name any two solid substances whose mixture can be separated by sublimation.
Q 44.
What are the characteristics of mixture?
Q 45.
What is meant by solute and solvent?
Q 46.
Why do fish go in deep waters during day light?
Q 47.
Based on the type of solvent, how solutions are classified?
Q 48.
Why air is a mixture not a compound? Give reasons.
Q 49.
What are suspensions? Explain with an example.
Q 50.
Winnowing works on what property?
