PLS HELP URGENT
1. Which of the following causes the temperature of a substance to remain constant while it is undergoing a change in its state?
(a) Latent heat (b) Lattice energy (c) Loss of heat (d) None of these
2. Which of the following phenomena always results in the cooling effect?
(a) Condensation (b) Evaporation (c) Sublimation (d) Melting
3. Which of the following cannot be considered a form of matter?
(a) Atom (b) water (c) Humidity (d) Electron
4. When heat is constantly supplied by a burner to boiling water, then the temperature of water during vaporisation:
(a) Rises slowly (b) Rises rapidly (c) First rises and then becomes constant (d) Does not rise at all
5. Which of the following will increase on raising the temperature?
(a) Condensation (b) Compression of gases (c) Diffusion (d) Deposition
Answers
Answer:
1) During the charge of state of matter, the temperature remains same due to latent heat.
The heat which is supplied to phase change is used up for breaking the bonds between the molecules of the substance.
Latent heat is the heat that is required to convert a solid into a liquid/vapor, or a liquid into a vapour, without charge of temperature.
So, the correct option is 'A'
2) (b) Evaporation
3) (c) Humidity
4) (d) Does not rise at all
5) (c) As temperature increases, kinetic energy of gases increases and now molecular will move faster than earlier hence they will have high evaporation, diffusion, expansion of gases as all these properties are directly proportional to temperature.
Solubility depends on particular reaction, if reaction is endothermic then solubility increases otherwise it will decrease.
Answer:
1)Latent heat
2)Evaporation
3)Humidity
4)Rises slowly
5)Evaporation,Diffusion,Expansion of gases