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प्रश्न
How is the impurity of iron present in several substances removed in industries ?
उत्तर
The impurity of iron present in several substances in the industries is removed using electromagnets. Waste materials supplied to the industries contain a number of scrap metals including iron.
Iron objects stick to the electromagnet and are collected at a separate place, leaving behind other objects.
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संबंधित प्रश्न
Match the following
| Column A | Column B | ||
| (a) | Molecules | (i) | Water boils |
| (b) | 100° C | (ii) | Evaporation |
| (c) | 0° C | (iii) | Changes from solid to gas |
| (d) | At all temperatures | (iv) | Matter |
| (e) | Camphor | (v) | Water freezes |
Name the processes involved in two cases.
What are molecules ?
Out of solids, liquids and gases, which one has :
- maximum movement of particles ?
- maximum interparticle attractions ?
- minimum spaces between particles ?
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?
What elements do the following compounds contain ?
Sugar, Common salt
Which of the following substances are elements ?
Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine
Name a metal which has no fixed shape.
How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
If 25 mL of acetone is present in 150 mL of its aqueous solution, calculate the concentration of solution.
How will you differentiate between a suspension and a colloid ?
Which of the following represents the solubility of sugar in water at 20°C ?
Name one pair of liquids which can be separated by using a separating funnel.
A standard sheet of paper is about ______ of atoms thick
Which of the following are homogeneous in nature?
(i) ice
(ii) wood
(iii) soil
(iv) air
______ is so hard that it can scratch glass.
The phenomenon of Evaporation takes place at the ______ of a liquid.
Define the term matter.
