Question:
What is meant by saying that metals are malleable and ductile ?
Answer:
Metals are Malleable. This means that metals can be beaten into thin sheets with a hammer (without breaking). Gold and silver metals are some of the best malleable metals.
Metals are Ductile. This means that metals can be drawn (or stretched) into thin wires. All the
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 one pair of liquids which can be separated by using a separating funnel.
Q 4.
How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
Q 5.
Define Brownian movement in colloids.
Q 6.
Name the property :
(a) which allows metals to be hammered into thin sheets.
(b)
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.
Name one pair of substances whose mixture can be separated by fractional distillation.
Q 9.
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 10.
What is meant by saying that metals are malleable and ductile ?
Q 11.
Give two reasons for supposing that water is a compound and not a mixture.
Q 12.
What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?
Q 13.
Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.
Q 14.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 15.
On the basis of composition, how matter is classified?
Q 16.
What is saturated solution? Explain with an example.
Q 17.
How are sol, solution and suspension different from each other?
Q 18.
Calculate the mass of glucouse and mass of water required to make 200g of 25% solution of glucouse.
Q 19.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Q 20.
What is an unsaturated solution?
Q 21.
Explain with an example what is a colloid?
Q 22.
What is an emulsion? Give examples
Q 23.
Name a metal which is soft and a non-metal which is hard.
Q 24.
Name a non-metal which is a good conductor of electricity.
Q 25.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
Q 26.
What are different categories of pure substance?
Q 27.
What are non-aqueous solutions?
Q 28.
What are the reasons for separating the constituents of a mixture?
Q 29.
How crystallization is better than evaporation?
Q 30.
Name the elements are in liquid state at room temperature.
Q 31.
What are pure substances ? Give two examples of pure substances.
Q 32.
What are the kinds of mixture?
Q 33.
Describe sieving method.
Q 34.
Give examples of liquids that are
(i) completely miscible
(ii) partially miscible
(iii) practically immiscible
Q 35.
Which of the following is a mixture ?Salt, Air, Water, Alum, Sugar
Q 36.
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
Q 37.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Q 38.
How is cream separated from milk ?
Q 39.
What is a compound? Give an example.
Q 40.
What is a solution? What are the properties of a solution?
Q 41.
What are aqueous solutions?
Q 42.
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 43.
What is Chromatography?
Q 44.
Who used the term 'element' first time?
Q 45.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 46.
Which of the following will show Tyndall effect ? Why ?
(a) Salt solution
(b) Starch solution
(c)Milk
Q 47.
Name any two solid substances whose mixture can be separated by sublimation.
Q 48.
Name two properties of a substance to check its purity?
Q 49.
What are the characteristics of mixture?
Q 50.
What is meant by solute and solvent?
