Question:
What difference in the properties of common salt and sand would enable you to separate a mixture of these two substances ?
Answer:
Common salt is soluble in water whereas sand is insoluble in water. So, a mixture of common salt (sodium chloride), and sand can also be separated by using water as solvent.ammonium chloride, potassium nitrate and potash alum are also soluble in water, but carbon and sulphur are insoluble in water.
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.
Define Brownian movement in colloids.
Q 7.
What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?
Q 8.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
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.
Calculate the mass of glucouse and mass of water required to make 200g of 25% solution of glucouse.
Q 11.
Give two reasons for supposing that water is a compound and not a mixture.
Q 12.
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
Q 13.
Name the process which can be used to separate a mixture of salt solution and sand.
Q 14.
State the differences between compounds and mixtures.
Q 15.
What are non-aqueous solutions?
Q 16.
What is an unsaturated solution?
Q 17.
What is saturated solution? Explain with an example.
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.
Which of the two will scatter light: soap solution or sugar solution ? Why ?
Q 25.
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
Q 26.
Name the property of any one of the components which can be used for separating the following mixture : Salt and Camphor
Q 27.
Name the process which is used in milk dairies to separate cream from milk.
Q 28.
What are different categories of pure substance?
Q 30.
Explain with an example what is a colloid?
Q 31.
What are different ways to separate solid mixtures?
Q 32.
Who used the term 'element' first time?
Q 33.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 34.
Give examples of liquids that are
(i) completely miscible
(ii) partially miscible
(iii) practically immiscible
Q 35.
State whether the following statement is true or false : Milk is a pure substance.
Q 36.
Which of the following is a mixture ?Salt, Air, Water, Alum, Sugar
Q 37.
What is the general name of the materials which contain at least two pure substances and show the properties of their constituents ?
Q 38.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Q 39.
How is cream separated from milk ?
Q 40.
Based on the type of solvent, how solutions are classified?
Q 41.
Name the elements are in liquid state at room temperature.
Q 42.
Classify the following into elements and compounds :
(i)
Q 43.
Is air a mixture or a compound ? Give three reasons for your answer.
Q 44.
Name the process you would use to separate a mixture of anthracene and copper sulphate ?
Q 45.
Name the process by which the various gases of the air are separated.
Q 46.
Name any two solid substances whose mixture can be separated by sublimation.
Q 47.
How will you separate a mixture of chalk powder and water ?
Q 48.
(a) Name the process by which all the dye can be recovered from black ink.
(b) Name the process by which the various dyes' (coloured materials) present in black ink can be separated.
Q 49.
What are the characteristics of mixture?
Q 50.
What is a solution? What are the properties of a solution?
