Advertisements
Advertisements
प्रश्न
Which of the following are ‘pure substances’ ?
Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air
Advertisements
उत्तर
Iron and mercury are pure substances because these are elements. Hydrochloric acid, calcium oxide, and ice are also pure substances, as they are compounds.
APPEARS IN
संबंधित प्रश्न
Solids have definite shape and definite volume.
Name the terms for the change of vapour into a liquid.
Define matter. Give four examples of matter.
The three important metalloids are.............................. and ..........................
Name a metal which has no fixed shape.
Which of the following is not an element ?
A, B and C are all liquids. Liquid A has a comparatively low boiling point. On heating, liquid A vaporises completely without leaving behind any residue. Liquid A is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid B has a very high boiling point. It also vaporises completely on heating, without leaving any residue. Liquid B is a conductor of electricity and used in making thermometers. Liquid C has a moderate boiling point. On heating, liquid C vaporises leaving behind a white solid D which is used in cooking vegetables. The condensation of vapours from C give a liquid E which turns anhydrous CuSO4 to blue.
(a) Which liquid could be an element ? Name this element.
(b) Which liquid could be a mixture ? Name this mixture.
(c) Which liquid could be a compound ? Name this compound.
(d) What could the solid D be ?
(e) What do you think is liquid E ?
Which of the following will show Tyndall effect ? Why ?
- Salt solution
- Starch solution
- Milk
- Copper sulphate solution
What is meant by the concentration of a solution ?
Differentiate between a saturated and an unsaturated solution. How will you test whether a given solution is saturated or not ?
A carpenter wants to separate iron nails from saw-dust. Which method of separation should he choose ?
Name the process which can be used to recover salt from an aqueous salt solution.
Name the process by which common salt is obtained from sea-water.
How would you separate iodine from a mixture of iodine and common salt ?
Pure copper sulphate can be obtained from an impure sample by the process of :
What's the solution?
We need to rub salt on a corncob, but only salt crystals are available.
Boiling refers to the process by which a substance changes from the liquid to the gaseous state at its ______ point.
Gas-solid is ______.
Write scientific reason.
Lemon sherbat has sweet, sour and salty taste and it can be poured in a glass.
Define the term matter.
