Question:
How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
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.
How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
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.
Define Brownian movement in colloids.
Q 7.
What is saturated solution? Explain with an example.
Q 8.
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 9.
What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?
Q 10.
What is an unsaturated solution?
Q 11.
Name the elements are in liquid state at room temperature.
Q 12.
Who used the term 'element' first time?
Q 13.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Q 14.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 15.
Calculate the mass of glucouse and mass of water required to make 200g of 25% solution of glucouse.
Q 16.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 17.
Name a non-metal which is a good conductor of electricity.
Q 18.
Name the property :
(a) which allows metals to be hammered into thin sheets.
(b)
Q 19.
What is meant by saying that metals are malleable and ductile ?
Q 20.
Give two reasons for supposing that water is a compound and not a mixture.
Q 21.
Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.
Q 22.
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
Q 23.
What are non-aqueous solutions?
Q 24.
Explain with an example what is a colloid?
Q 25.
How are sol, solution and suspension different from each other?
Q 26.
What is an emulsion? Give examples
Q 27.
Give examples of liquids that are
(i) completely miscible
(ii) partially miscible
(iii) practically immiscible
Q 28.
Name a metal which is soft and a non-metal which is hard.
Q 29.
What are different categories of pure substance?
Q 31.
State the differences between compounds and mixtures.
Q 32.
How crystallization is better than evaporation?
Q 33.
What are the differences and similarities between concentration and solubility?
Q 34.
Which of the following is a mixture ?Salt, Air, Water, Alum, Sugar
Q 35.
Is air a mixture or a compound ? Give three reasons for your answer.
Q 36.
Name a metal :
(a) which can be easily cut with a knife
(b) which forms amalgams
©which has not fixed shape
(d) which has a low melting point
(e) which is yellow in colour
Q 37.
Which of the two will scatter light: soap solution or sugar solution ? Why ?
Q 38.
Name the property of any one of the components which can be used for separating the following mixture : Salt and Camphor
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.
Name two properties of a substance to check its purity?
Q 42.
What are the kinds of mixture?
Q 43.
What is a compound? Give an example.
Q 44.
What is meant by solute and solvent?
Q 45.
What is meant by Solubility?
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.
What are the advantages of preparing solutions?
Q 49.
What are the physical states of dispersed phase and dispersion medium of a cloud?
Q 50.
What are different ways to separate solid mixtures?
