Question:
What is a dry ice and what are its properties?
Answer:
Solid carbon dioxide ( is known as dry ice. It is stored under high pressure. Solid CO2 gets converted directly to gaseous state on decrease of pressure to 1 atmosphere without coming into liquid state (i.e. sublimes). This is the reason that solid carbon dioxide is also known as dry ice. It is mainly used as cooling agent because its temperature is very low than water-ice. Dry ice is commonly used in theaters and in movies to produce the effect of fog.
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 is evaporation? Why does evaporation cause cooling?
Q 7.
List any five physical properties of liquids.
Q 8.
Which state of matter is most easily compressible?
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.
Define transpiration.
Q 13.
Arrange the following substances in increasing order of intermolecular force of attraction: water, sugar, oxygen
Q 14.
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.
Our own bodies contain examples of all three states of matter. Can you identify these?
Q 22.
How matter is classified in terms of composition?
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.
What is the physical state of water at the following temperatures? (a) 25 °C (b) 0 °C (c) 100 °C
Q 27.
In which case evaporation of water will be faster i.e. near the sea or far away from the sea.
Q 28.
Why do diffusion become faster at higher temperatures?
Q 29.
Why do gases diffuse rapidly?
Q 30.
Which of the following are matter?
Chair, Air, Love, Smell, Hate, Almonds, Thought, Cold, Cold drinks, Smell of perfume
Q 31.
Convert the following temperature to Celsius scale: (a) 300 K (b) 573 K
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.
Name the process by which a drop of ink spreads in a beaker of water.
Q 35.
What is the (a) common unit of temperature, and (b) SI unit of temperature ?
Q 36.
What is meant by saying that the latent heat of vaporisation of water is 22.5 x
Q 37.
What factors affect the rate of evaporation?
Q 38.
What is the general name of : (a) rigid form of matter ? (b) fluid forms of matter ?
Q 39.
What are the conditions for 'something' to be called 'matter' ?
Q 40.
Honey is more viscous than water. Can you suggest why ?
Q 41.
State whether the following statement is true or false : Solid carbon dioxide is stored under low pressure.
Q 42.
Write the full forms of the following :(a) LPG (b) CNG
Q 43.
What are the characteristics of matter?
Q 44.
Differences among solids, liquids and gases.
Q 45.
The Kelvin scale temperature is 0 K. What is the corresponding Celsius scale temperature ?
Q 46.
Give the usual name for the following :Heat required to change the state of a substance without changing the temperature.
Q 47.
Give reasons to justify: (a) Water at room temperature is a liquid. (b) An iron almirah is solid.
Q 48.
Explain with an experiment to show gases do not have fixed shape or volume.
Q 49.
Is smell of garlic or perfume a matter?
Q 50.
What is the scientific name of particles which make up matter ?
