Question:
Define the following terms:
a. Melting point
b. Freezing point
c. Boiling point
Answer:
a. The temperature at which solid changes into liquid is called its melting point. b. The temperature at which liquid changes into solid. c. The temperature at which liquid changes into vapors is termed as its boiling point.
Matter in Our Surroundings
Q 1.
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.
What do you mean by the term Volume?
Q 7.
Which state of matter is most easily compressible?
Q 8.
Define the term Volatile Liquid.
Q 9.
What is evaporation? Why does evaporation cause cooling?
Q 10.
List any five physical properties of liquids.
Q 11.
Arrange the following substances in increasing order of intermolecular force of attraction: water, sugar, oxygen
Q 12.
Why solids cannot be compressed like gases?
Q 13.
Define transpiration.
Q 15.
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 16.
How matter is classified in terms of composition?
Q 17.
What are the differences between boiling and evaporation?
Q 18.
Our own bodies contain examples of all three states of matter. Can you identify these?
Q 19.
Define evaporation.
Q 20.
What do you mean by the following terms:
a. Evaporation
b. Sublimation
c. Condensation
Q 21.
Define Latent Heat of Fusion and Latent Heat of vaporisation.
Q 22.
Why is light not considered matter?
Q 23.
How can matter change its state?
Q 24.
How vapour is different from gases? Give examples of each.
Q 25.
Why do diffusion become faster at higher temperatures?
Q 26.
In which case evaporation of water will be faster i.e. near the sea or far away from the sea.
Q 27.
What is the physical state of water at the following temperatures? (a) 25 °C (b) 0 °C (c) 100 °C
Q 28.
Which of the following state does not exist at room temperature conditions: a) Solids b) Liquids c) Gas d) Plasma
Q 29.
Which of the following are matter?
Chair, Air, Love, Smell, Hate, Almonds, Thought, Cold, Cold drinks, Smell of perfume
Q 30.
Convert the following temperature to Celsius scale: (a) 300 K (b) 573 K
Q 31.
Why does the temperature of a substance remain constant during melting and boiling even when heat is being supplied to it continuously?
Q 32.
Why do gases diffuse rapidly?
Q 33.
Explain compressibility in gases with an example?
Q 34.
Why is ice at 273 K more effective in cooling than water at the same temperature?
Q 35.
What factors affect the rate of evaporation?
Q 36.
The Kelvin scale temperature is 0 K. What is the corresponding Celsius scale temperature ?
Q 37.
Name the process by which a drop of ink spreads in a beaker of water.
Q 38.
Define the following terms:
a. Melting point
b. Freezing point
c. Boiling point
Q 39.
State whether the following statement is true or false : Solid carbon dioxide is stored under low pressure.
Q 40.
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 41.
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 42.
The Kelvin temperature is 270 K. What is the corresponding Celsius scale temperature ?
Q 43.
Explain with an experiment to show gases do not have fixed shape or volume.
Q 44.
Honey is more viscous than water. Can you suggest why ?
Q 45.
The boiling point of water is 100°C. Express this in SI units (Kelvin scale).
Q 46.
Convert the temperature of 373°C to the Kelvin scale.
Q 47.
Give the usual name for the following :Heat required to change the state of a substance without changing the temperature.
Q 48.
What is the (a) common unit of temperature, and (b) SI unit of temperature ?
Q 49.
Write the relation between Kelvin scale and Celsius scale of temperature.
Q 50.
(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.
