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प्रश्न
How is the impurity of iron present in several substances removed in industries ?
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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
Select the correct alternative
The molecules can move freely anywhere in
- gases
- liquids
- solids
- none of the above
Name a liquid which can be classified as a pure substance and conducts electricity.
Classify the following as elements or compounds :
Iron, Iron sulphide, Sulphur, Chalk, Washing soda, Sodium, Carbon, Urea
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 ?
Define solvent.
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.
Which of the following are chemical changes and which physical ? Give reason.
- a glass bottle breaking
- coal burning in air
- making a cake
- wool being knitted into a sweater
What is the difference between colloids and suspensions ?
When the solid A is added to water, it dissolves with the evolution of a lot of heat and making little explosions to form two products B and C. The properties of products B and C are entirely different from those of solid A as well as water. Moreover, products B and C cannot be reconverted into solid A and water. When another solid D is added to water, it dissolves with the absorption of a little heat to form a product E which cools down. The product E shows the properties of both, solid D as well as water. Moreover, product E can be converted into solid D and water.
(a) What type of change occurs when solid A is dissolved in water ? Why ?
(b) What type of change occurs when solid D is dissolved in water ? Why ?
(c) Name a metal which you think could behave like solid A. Also name the products B and C.
(d) Name the solid D if it is the one which is used in making ordinary dry cells.
(e) Name the process by which D can be recovered from E.
Name the process by which all the dye can be recovered from black ink.
Fill in the following blanks with suitable words :
The separation of liquids by fractional distillation is based on the difference in their .....................
Explain how, impure copper sulphate can be purified by crystallisation.
The liquid air has three components X, Y and Z whose boiling points are : –186°C, –183°C and –196°C,
respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed
up slowly :
(a) Which component will be collected from near the bottom of the fraction distillation column ? Why ?
(b) Which component will be collected from the top part of the fractional distillation column ? Why ?
(c) Which component will be collected from the middle part of the fractional distillation column ? Why ?
(d) What could the component X, Y and Z be ?
Which among the following ______ will get attracted to by magnet?
Why wires cannot be drawn from materials such as stone or wood?
The particles in the matter are extremely small and can be seen even with a powerful microscope.
In Aerosol the dispersed phase is liquid and the dispersion medium is gas.
Define the term matter.
Define the term matter.
