Science Question Answer (1 Marks)

Name the source from which nitrogen and oxygen are obtained on a large scale.

Name a metal:
Which has a low melting point.

What are pure substances? Give two examples of pure substances.

Which of the following contains less solute at a given temperature and pressure?
Unsaturated solution or Saturated solution.

Name the process which can be used to purify an impure sample of copper sulphate.

What is the general name of the process by which tea-leaves are separated from prepared tea?

Name the process which is used in milk dairies to separate cream from milk.

What is the other name for impure substances? Give two examples of impure substances.

A carpenter wants to separate iron nails from saw-dust. Which method of separation should he choose?

Which of the following is a mixture?

Salt, Air, Water, Alum, Sugar

Choose one term from the following which includes the other three:
Aerosol, emulsion, colloid, sol.

Name the property:

Which allows metals to be hammered into thin sheets.

Name one solid, one liquid and one gaseous non-metal.

Whose one of the allotropic forms is a good conductor of electricity. Name the allotrope.

Name a metal which is soft and a non-metal which is hard.

Out of a colloid, solution and a suspension:
Which one has the smallest particles?

Name a metal:
Which is yellow in colour.

What differences in the properties of oil and water enable their separation by a separating funnel?

Name a metal:
Which has no fixed shape.

Name a metal:
Which form amalgams.

Give reason why:
Graphite is used for making electrode in a dry cell.

Name a non-metal:
Which is known to form the largest number of compounds.

What is meant by saying that non-metals are brittle?

Name a non-metal:
Which is required for combustion.

Name any two solid substances whose mixture can be separated by sublimation.

Which type of elements, metals or non-metals, show the property of brittleness?

State whether colloidal solutions are homogeneous or heterogeneous.

Name a metal:
Which can be easily cut with a knife.

State whether the following statements are true or false:
Salt and water can be recovered from an aqueous salt solution by the process of evaporation.

What do you understand by the statement "the solubility of copper sulphate in water at 20°C is 20.7g"?

What elements do the following compounds contain?
Sugar, Common salt

State one application of centrifugation.

Name one metal and one non-metal which exist as liquids at room temperature.

What difference in the property of two miscible liquids enables their separation by fractional distillation?

Name the process by which common salt is purified.

Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.

Name the process you would use to separate a mixture of anthracene and copper sulphate?

What is the most common way of expressing the concentration of a solution?

Out of a colloid, solution and a suspension:
Which one has the largest particles?

Give reason why:
Copper metal is used for making electric wires.

What is the general name of the materials which contain at least two pure substances and show the properties of their constituents?

Other than carbon which shows allotropy.

How would you confirm that a colourless liquid given to you is pure water?

Name the process you would use to separate a mixture of water and alcohol.

Name the process by which the various ‘dyes’ (coloured materials) present in black ink can be separated.

Name a liquid which can be classified as a pure substance and conducts electricity.

What happens when the temperature of a saturated sugar solution is increased?

Which of the following are not compounds?
Chlorine gas, Potassium chloride, Iron powder, Iron sulphide, Aluminium foil, Iodine vapour, Graphite, Carbon monoxide, Sulphur powder, Diamond.

State any two properties for believing that aluminium is a metal.

Name the property:

Which enables metals to be drawn into wires.

Which technique can be used to detect and identify traces of poison present in the stomach wash of a person?

Name the process by which the various gases of the air are separated.

Name the property of one of the constituents which can be used to separate a mixture of salt and iodine.

Name three mixtures found in nature.

How would you separate a mixture of sugar and salt?

How much water should be added to 15 grams of salt to obtain 15 percent salt solution?

Which technique is used in a washing machine to squeeze out water from wet clothes while drying?

Name the solvent you would use to separate a mixture of sulphur and carbon.

Name the process by which all the dye can be recovered from black ink.

Name the process which can be used to recover salt from and aqueous salt solution.

Which of the following is a sol?
Saving cream, Milk, Fog, Soap solution, Hairspray.

Explain what happens when a beam of light is passed through a colloidal solution.

What is meant by caying that metals are sonorous?

What is meant by the concentration of a solution?

State one instance where water undergoes a physical change and one in which it undergoes a chemical change.

What are the three general classes of matter? Give one example of each type.

Name one pair of substances whose mixture can be separated by fractional distillation.

Name the process you would use to separate oil from water.

Which of the following do not exhibit Tyndall effect?
Starch solution, Sugar solution, Ink, Salt solution, Copper sulphate solution, Ammonium chloride solution, Fog, Smoke, Car exhausts.

State two physical properties on the basis of which metals can be distinguished from non-metals.

In the following set of substances, one item does not belong to the set. Select this item and explain why it does not belong to the set:
Hydrogen, Oxygen, Steam, Chlorine.

Classify the following as elements or compounds:
Iron, Iron sulphide, Sulphur, Chalk, Washing soda, Sodium, Carbon, Urea

Name the process by which common salt is obtained from sea-water

What is the other name of homogenous mixtures?

Name one element, one compound and one mixture.

“The properties of the product are different from those of the constituents”. State whether this statement best describes an element, a compound or a mixture.

What name is given to those elements which are neither good conductors of electricity like copper nor insulators like sulphur?

Which method can be used to separate a mixture of naphthalene and common salt?

What is meant by saying that metals are lustrous?

What type of magnet is fitted on a crane to separate scarp iron objects from a heap of waste materials in factories?

How will you separate a mixture of chalk powder and water?

What is meant by saying that metals are malleable and ductile?

Name a non-metal which is a good conductor of electricity.

What difference in the properties of common salt and sand would enable you to separate a mixture of these two substances?

Name the property of any one of the components which can be used for separation the following mixture:
Salt and Camphor.

Which of the following are ‘pure substance’?
Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air.

Name the process which can be used to separate a mixture of salt solution and sand.

Name a non-metal:
Which is lustrous.

Name one pair of substances whose mixture can be separated completely by distillation.

Which of the following substances are elements?
Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine

Choose the solutions from among the following mixtures:
Soil, Sea-water, Air, Coal, Soda-water

Name the process you would use to separate a mixture of two miscible liquids (like acetone and water).