Question:
Why is ice at 273 K more effective in cooling than water at the same temperature?
Answer:
Ice at 273K or 0 C can absorb a large amount of heat energy as latent heat of fusion to get converted to water state. Therefore Ice at 273K is more effective in cooling.
Matter in Our Surroundings
Q 2.
What is SI unit of temperature? Give mathematical relation also.
Q 3.
What do you mean by change in state?
Q 4.
How matter is classified in terms of physical state?
Q 5.
What are the ways a gas can be liquefied?
Q 6.
List any five physical properties of liquids.
Q 7.
Which state of matter is most easily compressible?
Q 8.
What is evaporation? Why does evaporation cause cooling?
Q 9.
What do you mean by the term Volume?
Q 10.
Define the term Volatile Liquid.
Q 11.
Why solids cannot be compressed like gases?
Q 12.
Arrange the following substances in increasing order of intermolecular force of attraction: water, sugar, oxygen
Q 13.
Define transpiration.
Q 15.
What are the differences between boiling and evaporation?
Q 16.
What do you mean by the following terms:
a. Evaporation
b. Sublimation
c. Condensation
Q 17.
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 18.
Define evaporation.
Q 19.
Define Latent Heat of Fusion and Latent Heat of vaporisation.
Q 20.
Why is light not considered matter?
Q 21.
How matter is classified in terms of composition?
Q 22.
Our own bodies contain examples of all three states of matter. Can you identify these?
Q 23.
How can matter change its state?
Q 24.
How vapour is different from gases? Give examples of each.
Q 25.
Which of the following state does not exist at room temperature conditions: a) Solids b) Liquids c) Gas d) Plasma
Q 26.
Why do diffusion become faster at higher temperatures?
Q 27.
In which case evaporation of water will be faster i.e. near the sea or far away from the sea.
Q 28.
What is the physical state of water at the following temperatures? (a) 25 °C (b) 0 °C (c) 100 °C
Q 29.
Why do gases diffuse rapidly?
Q 30.
Convert the following temperature to Celsius scale: (a) 300 K (b) 573 K
Q 31.
Which of the following are matter?
Chair, Air, Love, Smell, Hate, Almonds, Thought, Cold, Cold drinks, Smell of perfume
Q 32.
Why does the temperature of a substance remain constant during melting and boiling even when heat is being supplied to it continuously?
Q 33.
Convert the temperature of 373°C to the Kelvin scale.
Q 34.
What factors affect the rate of evaporation?
Q 35.
What is meant by saying that the latent heat of vaporisation of water is 22.5 x
Q 36.
Name the process by which a drop of ink spreads in a beaker of water.
Q 37.
Write the full forms of the following :(a) LPG (b) CNG
Q 38.
Honey is more viscous than water. Can you suggest why ?
Q 39.
The Kelvin scale temperature is 0 K. What is the corresponding Celsius scale temperature ?
Q 40.
What is the (a) common unit of temperature, and (b) SI unit of temperature ?
Q 41.
State whether the following statement is true or false : Solid carbon dioxide is stored under low pressure.
Q 42.
(a) Define the term 'latent heat of vaporisation' of a liquid. What is the value of the latent heat of vaporisation of water ?
(b) Draw a labelled diagram of the experimental set-up to study the latent heat of vaporisation of water.
Q 43.
Give reasons to justify: (a) Water at room temperature is a liquid. (b) An iron almirah is solid.
Q 44.
What are the conditions for 'something' to be called 'matter' ?
Q 45.
Explain with an experiment to show gases do not have fixed shape or volume.
Q 46.
Why is ice at 273 K more effective in cooling than water at the same temperature?
Q 47.
Differences among solids, liquids and gases.
Q 48.
Why do solids expand a bit on heating and contract a bit on cooling?
Q 49.
What is the general name of : (a) rigid form of matter ? (b) fluid forms of matter ?
Q 50.
The Kelvin temperature is 270 K. What is the corresponding Celsius scale temperature ?
