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प्रश्न
State whether the following statement are true or false :
Salt and water can be recovered from an aqueous salt solution by the process of evaporation.
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उत्तर
True. As water can undergo the process of evaporation forming vapours, which can be collected in a separate container and can be easily separated from a salt solution.
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संबंधित प्रश्न
Define matter.
The best evidence for the existence and movement of particles in liquids was provided by :
Explain why, osmosis can be considered to be a special kind of diffusion. Classify the following into
(i) osmosis, and (ii) diffusion :
- swelling up of a raisin on keeping in water
- spreading of virus on sneezing
- earthworm dying on coming in contact with common salt
- shrinking of grapes kept in thick sugar syrup
- preserving of pickles in salt
- spreading of smell of cake being baked in the kitchen
- aquatic animals using oxygen dissolved in water during respiration
When extremely small particles X derived from the anther of a flower were suspended in a liquid Y and observed through a microscope, it was found that the particles X were moving throughout the liquid Y in a very zig-zag way. It was also observed that warmer the liquid Y, faster the particles X moved on its surface.
- What could particles X be ?
- What do you think liquid Y is ?
- What is the zig-zag movement of X known as ?
- What is causing the zig-zag movement of particles X ?
- Name the scientist who discovered this phenomenon.
- What does this experiment tell us about the nature of liquid Y?
Which of the following is a mixture ?
Salt, Air, Water, Alum, Sugar
What elements do the following compounds contain ?
Sugar, Common salt
Name a metal which can be easily cut with a knife.
The property/properties which enable copper metal to be used for making electric wires is/are :
A solution contains 5.6 mL of alcohol mixed with 75 mL of water. Calculate the concentration of this solution.
State whether the following statement is true or false :
Sponge is an example of solid sol.
In what respects does a true solution differ from a colloidal solution ?
Define Sol and give one example.
What is meant by the concentration of a solution ?
Name the process which is used in milk dairies to separate cream from milk.
Name the process you would use to separate a mixture of water and alcohol.
Explain the meaning of the term ‘matter’.
The non S I and S I units of some physical quantities are given in column A and column B respectively. Match the units belonging to the same physical quantity:
| (A) | (B) | ||
| (a) | degree celsius | (i) | kilogram |
| (b) | centimetre | (ii) | pascal |
| (c) | gram per centimetre cube | (iii) | metre |
| (d) | bar | (iv) | kelvin |
| (e) | milligram | (v) | kilogram per metre cube |
Solids possess very high kinetic energy.
Write a scientific reason.
Lemon sherbat has a sweet, sour and salty taste and it can be poured in a glass.
Define the term matter.
