Question:
What are the differences between boiling and evaporation?
Answer:
| No. | Boiling | Evaporation |
|---|
| 1 | It occurs at a specific temperature. | It occurs at all temperatures. |
| 2 | It requires heat energy to be supplied by external sources. | In general, liquid absorbs heat energy from its surroundings. |
| 3 | It takes place throughout the liquid. | It is a surface phenomenon and occurs only at the surface of the liquid. |
| 4 | It is not accompanied by cooling. The temperature of the liquid has increased. | In this process, the region surrounding the evaporating liquid gets cooler. |
| 5 | It is a rapid and noisy process. | It is a slow and quiet process. |
| 6 | Temperature of the liquid remains constant at the boiling point. | Usually the temperature of liquid drops. |
Matter in Our Surroundings
Q 1.
What is SI unit of temperature? Give mathematical relation also.
Q 3.
How matter is classified in terms of physical state?
Q 4.
What do you mean by change in state?
Q 5.
List any five physical properties of liquids.
Q 6.
What is evaporation? Why does evaporation cause cooling?
Q 7.
What do you mean by the term Volume?
Q 8.
What are the ways a gas can be liquefied?
Q 9.
Why solids cannot be compressed like gases?
Q 10.
Define the term Volatile Liquid.
Q 11.
Which state of matter is most easily compressible?
Q 12.
Define transpiration.
Q 13.
Arrange the following substances in increasing order of intermolecular force of attraction: water, sugar, oxygen
Q 15.
What are the differences between boiling and evaporation?
Q 16.
Define evaporation.
Q 17.
What do you mean by the following terms:
a. Evaporation
b. Sublimation
c. Condensation
Q 18.
Our own bodies contain examples of all three states of matter. Can you identify these?
Q 19.
Why is light not considered matter?
Q 20.
The mass per unit volume of a substance is called density (density=mass/volume). Arrange the following in order of increasing density:
Air, Exhaust from chimneys, Honey, Water, Chalk, Cotton and Iron.
Q 21.
Define Latent Heat of Fusion and Latent Heat of vaporisation.
Q 22.
How can matter change its state?
Q 23.
How matter is classified in terms of composition?
Q 24.
Why do gases diffuse rapidly?
Q 25.
Why do diffusion become faster at higher temperatures?
Q 26.
Which of the following state does not exist at room temperature conditions: a) Solids b) Liquids c) Gas d) Plasma
Q 27.
How vapour is different from gases? Give examples of each.
Q 28.
What is the physical state of water at the following temperatures? (a) 25 °C (b) 0 °C (c) 100 °C
Q 29.
In which case evaporation of water will be faster i.e. near the sea or far away from the sea.
Q 30.
Convert the temperature of 373°C to the Kelvin scale.
Q 31.
Name the process by which a drop of ink spreads in a beaker of water.
Q 32.
What is the (a) common unit of temperature, and (b) SI unit of temperature ?
Q 33.
What causes evaporation?
OR
Explain evaporation and its cooling effect in terms of kinetic energy of particles.
Q 34.
Give the usual name for the following :Heat required to change the state of a substance without changing the temperature.
Q 35.
Which of the following are matter?
Chair, Air, Love, Smell, Hate, Almonds, Thought, Cold, Cold drinks, Smell of perfume
Q 36.
What is the general name of : (a) rigid form of matter ? (b) fluid forms of matter ?
Q 37.
Write the full forms of the following :(a) LPG (b) CNG
Q 38.
The Kelvin temperature is 270 K. What is the corresponding Celsius scale temperature ?
Q 39.
Is smell of garlic or perfume a matter?
Q 40.
Why do solids expand a bit on heating and contract a bit on cooling?
Q 41.
Convert the temperature of 573 K to the Celsius scale.
Q 42.
The Kelvin scale temperature is 0 K. What is the corresponding Celsius scale temperature ?
Q 43.
Write the relation between Kelvin scale and Celsius scale of temperature.
Q 44.
Give reasons for the following observations. The smell of hot sizzling food reaches you several meters away, but to get smell from cold food you have to go close.
Q 45.
Convert the following temperature to Celsius scale: (a) 300 K (b) 573 K
Q 46.
Give reasons to justify: (a) Water at room temperature is a liquid. (b) An iron almirah is solid.
Q 47.
Why does the temperature of a substance remain constant during melting and boiling even when heat is being supplied to it continuously?
Q 48.
The mass per unit volume of a substance is called density.(density = mass/volume). Arrange the following in order of increasing density – air, exhaust from chimneys, honey, water, chalk, cotton and iron.
Q 49.
What are the conditions for 'something' to be called 'matter' ?
Q 50.
(a) What is evaporation ? State the various factors which affect evaporation.
Why does evaporation cool a liquid ?
