States of Matter
Knowledge-based Questions & Answers:
1.What is diffusion?
Answer: The tendency of solid, liquid or gas to spread spontaneously and uniformly in any medium is called diffusion.
2.What is effusion ?
Answer: The passage of gases from a high pressure zone to a low pressure zone through a fine pore is called effusion.
3.What is melting ?
Answer: The process of transforming a solid matter into liquid by means of applying heat is called melting.
4.What is melting point ?
Answer: At normal pressure (1 atmospheric pressure), the temperature at which a solid matter turns into liquid state is called the melting point of that solid.
5.What is boiling ?
Answer: The process of transforming a liquid matter into gas by means of heat is called boiling.
6.What is boiling point ?
Answer: At normal pressure (1 atmospheric pressure), the temperature at which a liquid matter turns into gaseous state is called the boiling point of that liquid.
7.What is sublimation ?
Answer: The process in which heating a solid directly turns that solid into gaseous substance instead of liquid, is called sublimation.
8.What is evaporation or vaporization?
Answer: The process of heating a liquid and turning it into gas is called evaporation or vaporization.
9. What is intermolecular distance?
Answer : The distance between the molecules of a substance is called intermolecular distance.
10. What is intermolecular force of attraction?
Answer : The force by which molecules of a substance remain together is called intermolecular force of attraction.
11. What is the kinetic theory of particles?
Answer: The attempt to prove the states of substances using intermolecular force of attraction and the kinetic force of the particles is known as the kinetic theory of particles.
12. What is distillation?
Answer. The process of heating a liquid into vapour and then retrieving the liquid from the vapour by cooling it is called distillation.
13. What is condensation?
Answer : The process of cooling the vapour into liquid substance is called condensation.
14. What is produced by burning wax?
Answer: Burning of wax produces CO2, H2O, heat and light energy.
15. What is diffusion rate?
Answer: The amount of space in a medium where solid, liquid or gaseous substance spontaneously spreads around in a unit time that is called the diffusion rate of the substance.
16. What is CNG?
Answer: Compressed methane gas at high pressure is called CNG or Compressed Natural Gas.
Comprehension-based Questions & Answers:
1.What do you mean by intermolecular force of attraction?
Answer : The force by which molecules of a substance remain together is called intermolecular force of attraction. The particles of solid substance have the highest intermolecular force of attraction. The intermolecular force of attraction of particles in liquids is less than solids. The molecules in gases stay further than those of liquids or solids so the intermolecular force of attraction is also very low among them.
2.What do you mean by kinetic theory of particles?
Answer : The attempt to prove the states of substances using intermolecular force of attraction and the kinetic force of the particles is known as the kinetic theory of particles. When the particles inside a substance remain in very high force of attraction, they stay together and cannot move that much. This is the solid state. When heat is applied on such a solid substance, the particles start to vibrate. When more heat is applied, the particles lose some of their force of attraction and they start some movement. This state of matter is called a liquid. When more heat is applied on this liquid state of the substance, the particles receive the heat and the kinetic force in them is increased. This kinetic force is increased to a level where they lose intermolecular force of attraction almost completely and start to move freely. This is the gaseous state. When more heat is applied to this state of the substance, the particles will only increase their speed of movement.
3.Between NH3, and HCI, which one diffuses earlier and why?
Answer : The substance that has low density or molar mass, it has higher diffusion rate. Because the molecules of a substance with low density stay at a distance from each other. As a result, diffusion occurs faster. The molar mass of NH3,(17) is less than the molar mass of HCI(36.5). So, NH3, has a higher diffusion rate than HCI.
Answer : Wax is a hydrocarbon with high molecular mass. When wax is burnt in the presence of atmospheric oxygen, it produces heat and light. When wax is burnt, at first it melts which is a physical change and then it burns which is a chemical change. We mainly get heat and light from burning wax. Wax + 02 -> CO2 + H2O + Energy (Heat + Light)
Answer : The substances that when heated directly turns from solid into a gaseous substance instead of a liquid, are called sublimated substances. When heated. ammonium chloride directly turns from solid into a gaseous substance instead of a liquid. This is why ammonium chloride is called a sublimated substance.