Question:
State the differences between compounds and mixtures.
Answer:
| Sno. | Compounds | Mixtures |
|---|
| 1. | It is made up of two or more elements that are chemically combined. | It is made up of two or more pure substances that are mixed physically. |
| 2. | A compound has definite melting and boiling points and density. | A mixture has no definite melting or boiling points and density. |
| 3. | The properties of a compound are entirely different from those of its constituents. | A mixture retains the properties of the components. |
| 4. | A compound is always homogeneous. | A mixture is heterogeneous, and some are homogeneous. |
| 5. | The constituents of a compound cannot be separated by physical means. | The components of a mixture can be separated by simple physical means,(dissolving, magnetic separation, heating, and filtration) |
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.
What are the properties of a colloid?
Q 3.
Classify the following as physical or chemical changes :
(i) Cooking of food
Q 4.
Choose one term from the following which includes the other three :
aerosol,
emulsion,
colloid,
sol
Q 5.
Name one pair of liquids which can be separated by using a separating funnel.
Q 6.
What is saturated solution? Explain with an example.
Q 7.
What are the physical states of dispersed phase and dispersion medium of a fog?
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 a solution? What are the properties of a solution?
Q 10.
What is meant by solute and solvent?
Q 11.
(a) What is meant by a solution ? Give two examples of solutions.
(b)What is a suspension ? Give two examples of suspensions.
(c)
Q 12.
Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.
Q 13.
What are the reasons for separating the constituents of a mixture?
Q 14.
Who gave the first explanatory definition of 'element'?
Q 15.
Name a metal which is soft and a non-metal which is hard.
Q 16.
(a) What is meant by (i) elements (ii) compounds, and (iii) mixtures ? Write down the names of two elements,two compounds and two mixtures.
(b) Classify the following into elements,
compounds and mixtures :
Marble,
Air,
Gold,
Brass,
Sand,
Diamond,
Graphite,
Petroleum,
Common salt,
Sea-water,
Chalk
Q 17.
Name one pair of substances whose mixture can be separated by fractional distillation.
Q 18.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Q 19.
What are non-aqueous solutions?
Q 20.
What is an unsaturated solution?
Q 21.
What is Chromatography?
Q 22.
Name the following :
(a) a lustrous liquid metal.
(b) a liquid non-metal
(c) a metal which can be cut with a knife
(d) a non-metal which is good conductor of electricity.
(e) an element which melts when kept on the palm.
(f) the best conductor of heat.
Q 23.
Name a non-metal which is a good conductor of electricity.
Q 24.
What is the general name of the materials which contain at least two pure substances and show the properties of their constituents ?
Q 25.
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
Q 26.
Which of the following will show Tyndall effect ? Why ?
(a) Salt solution
(b) Starch solution
(c)Milk
Q 27.
Name the property of any one of the components which can be used for separating the following mixture : Salt and Camphor
Q 28.
Name the apparatus you would use to separate oil from water.
Q 29.
What are the characteristics exhibited by a pure substance?
Q 30.
What is meant by a pure substance?
Q 31.
Based on the type of solvent, how solutions are classified?
Q 32.
Based on the amount of solute in the given solution, how solutions are classified?
Q 33.
What are aqueous solutions?
Q 34.
When we open the cap of a cola drink (or any carbonated beverage), why does excess of bubbles come out?
Q 35.
Why air is a mixture not a compound? Give reasons.
Q 36.
What are suspensions? Explain with an example.
Q 37.
What are the various methods to express concentration of a solution?
Q 38.
What are different ways to separate solid mixtures?
Q 39.
What is an emulsion? Give examples
Q 40.
State whether the following statement is true or false : Milk is a pure substance.
Q 41.
Which of the following is a mixture ?Salt, Air, Water, Alum, Sugar
Q 42.
What are pure substances ? Give two examples of pure substances.
Q 43.
A 5 per cent sugar solution means that:
(a)5 g of sugar is dissolved in 95 g of water.
(b)5 g of sugar is dissolved in 100 g of water.
Choose the correct answer.
Q 44.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
Q 45.
List the points of differences between homogeneous and heterogeneous mixtures.
Q 46.
What are the constituents of brass?
Q 47.
Why do fish go in deep waters during day light?
Q 48.
What are the physical states of dispersed phase and dispersion medium of a cloud?
Q 49.
Describe sieving method.
Q 50.
Name the technique to separate
(i) butter from curd
(ii) salt from sea-water
(iii) camphor from salt
