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प्रश्न
Explain how, the smell of food being cooked in the kitchen reaches us even from a considerable distance.
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उत्तर
The smell of food cooked in the kitchen reaches us even from a considerable distance because the tiny particles of the vapour of food mix with the air and move continuously in all directions. This process is called diffusion.
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संबंधित प्रश्न
Give a reason for the following observation.
Naphthalene balls disappear with time without leaving any solid.
Which of the two diffuses faster : a liquid or a gas?
A bottle of perfume was opened in a room. The smell of its vapours spread in the entire room. Name the property of gases which is responsible for this behaviour of perfume vapours.
Why do gases diffuse very fast?
Why does a gas exert pressure?
Look at the diagram on the right side. Jar A contains a red-brown gas whereas jar B contains a colourless gas. The two gas jars are separated by a galas plate placed between them
- What will happen when the glass plate between the two jars is pulled away?
- What name is given to the phenomenon which takes place?
- Name the brown gas which could be in jar A.
- Which is the colourless gas most likely to be present in jar B?
- Name one coloured solid and one colourless liquid which can show the same phenomenon.
A student placed a gas jar containing air in the upside down position over a gas jar full of red-brown bromine vapours. He observed that the red-brown colour spread upwards into the jar containing air. Based on this observation, the student concluded that it is only the bromine vapour which moves up and diffuses into air in the upper jar, the air from the upper jar does not move down by diffusion into the lower jar containing bromine vapours. Do you agree with this conclusion of the student? Give reason for your answer.
Explain why?
- A gas fills a vessel completely?
- Camphor disappears without leaving any residue.
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| Fig. I | Fig. II |
In figure-I, an air column of length ℓ1 is entrapped by a column of Hg of length 8 cm. In figure-II length of same air column at the same temperature is ℓ2. The `ℓ_1/ℓ_2` is:
(1 atm = 76 cm of Hg)
A gaseous mixture of He and O2 is found to have a density of 0.518 gL-1 at 25° C and 720 torr. The mass percent of helium in this mixture is ______.
