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प्रश्न
What is fractional distillation ? What is the use of fractionating column in fractional distillation ?
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उत्तर
Fractional distillation is a process of separating two or more miscible liquids by distillation. The distillate is collected in fractions, which boil at different temperatures. The principle behind this technique is the difference in boiling points of the liquids in the mixture.
The fractionating column is fitted in the neck of the distillation flask. Fractionating column provides different temperature zones inside the flask. The highest temperature is at the bottom and the lowest temperature is near its top.
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संबंधित प्रश्न
Intermolecular space is maximum in .......... less in ............ and the least in .........
Select the correct alternative
The molecules can move freely anywhere in
- gases
- liquids
- solids
- none of the above
Solids have definite shape and definite volume.
Fill in the blank
All matter is made up of tiny particles called ______
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
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The elements which normally exist in the liquid state are :
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(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 ?
Fill in the following blank :
Milk is a .................... solution but vinegar is a .................... solution.
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(a) What type of change occurs when solid A is dissolved in water ? Why ?
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(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.
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Match the physical quantities given in column A to their S I units given in column B:
| (A) | (B) | ||
| (a) | Pressure | (i) | cubic metre |
| (b) | Temperature | (ii) | kilogram |
| (c) | Density | (iii) | pascal |
| (d) | Mass | (iv) | kelvin |
| (e) | Volume | (v) | kilogram per cubic metre |
______ is so hard that it can scratch glass.
Solids do not flow.
Evaporation does form bubbles.
Gases do not diffuse very easily.
Define the term matter.
