Question

this are the questions plzz help me.
I will mark u as brainliest if u give an appropriate answer...

Answer 1

the process of turning from liquid into vapour.

"snow cover prevents evaporation of water from the soil"

Answer 2

Ans 1. This happens because the vapour pressure of some substances is higher when in the solid form than the liquid form. Vapour pressure is the pressure of the substance's vapour over the solid or liquid form when in equilibrium.

Substance (solid) --> substance (gas)   Kp1 = P(substance gas)

Substance (liquid) --> Substance (gas).  Kp2 = P (substance gas)

Kp1 > Kp2

Thus in reality, substance vapourises to gaseous form before converting to liquid form whereas in most other substances solids have very less vapour pressure than liquids and thus by the time solids convert to gases, they convert to liquids more easily and thus 'melt' rather than 'sublime'.

Ans 2. a. Because steam has more energy than water at same temp i.e. 100 ℃ .
Steam use latent heat of vaporisation to get vapourisze and water don't have this energy.
This latent ( hidden ) energy is the cause of more severe burns caused by steam than water

b. During summer, water kept in an earthen pot becomes cool because of the phenomenon of evaporation. Earthen pot has a large number of tiny pores in its walls and some of the water molecules continuously keep seeping through these pores to outside the pot.This water evaporates continuously and take the latent heat required for vaporisation from the remaining water. In this way, the remaining water loses heat and gets cooled.

Ans 3. The turning of any liquid into vapour is called Evaporation. The factors affecting the evaporation are:

1. Temperature. As the temperature increases, the rate of evaporation also increases.

2. Surface Area. As the Surface area increases, the rate of evaporation increases.

3. Density. As the density increases, the rate of evaporation decreases.

4. Wind Velocity. The velocity of the wind also affects the rate of evaporation. As the velocity of wind increases, the rate of evaporation increases.

Ans 4. Simple Distillation:

The vapor is immediately channeled into a condenser. Consequently, the distillate is not pure but rather its composition is identical to the composition of the vapors at the given temperature and pressure.



Fractional Distillation:

It is used in order to separate the components by repeated vaporization-condensation cycles within a packed fractionating column. This separation, by successive distillations, is also referred to as rectification.

Steam Distillation:

Steam Distillation is a method of distilling compounds which are heat-sensitive. The temperature of the steam is easier to control than the surface of a heating element. This allows a high rate of heat transfer without heating at a very high temperature.