Question

Which of the following will result in the increase of the rate of evaporation?
${\text{A}}{\text{.}}$ Increase of surface area, increase of temperature, decrease in humidity and increase in wind speed
${\text{B}}{\text{.}}$ Increase of surface area, decrease of temperature, decrease in humidity and decrease in wind speed
${\text{C}}{\text{.}}$ Decrease of surface area, increase of temperature, increase in humidity and increase in wind speed
${\text{D}}{\text{.}}$ Decrease of surface area, increase of temperature, decrease in humidity and decrease in wind speed

Answer 1

Hint- Here, we will firstly mention the effect of increase of temperature on the evaporation rate. Then, subsequently we will write down the effects of the surface area, humidity and wind speed on evaporation rate along with their reasons.

Step-By-Step answer:
As the liquid temperature is increased, the kinetic energy of the individual molecules which constitute the liquid is increased. This increase in energy makes it easier for the liquid molecules to conquer the intermolecular attraction forces (which bind the liquid molecules together) and to escape as a gas into the atmosphere.
The molecules of the liquid present at its surface during evaporation conquer the intermolecular forces of attraction to move away from the liquid form and escape into the atmosphere as a gas. Liquids are considered to have no definite form (they presume the form of the container in which they are placed). Therefore, the larger the container's surface area), the greater the amount of liquid molecules present at the surface. The greater the number of liquid molecules on the surface, the greater the amount of molecules that break away from the liquid and at a given point in time become a gas that leads to an increase in the evaporation rate.
There's a limit on how much ambient water vapour will collect. This limit is proportional to the temperature. Evaporation can be seen as a phase of equilibrium in which the amount of water vapour in the atmosphere achieves balance with the amount of water in the liquid surface. Therefore, the greater the quantity of water vapour over the liquid in the atmosphere, the slower the evaporation rate. It should also be noted that a rise in temperature with constant humidity would lead to an increase in evaporation rate, as hot air will retain more water vapour. So, humidity is inversely proportional to the evaporation rate.
Evaporation increases atmospheric humidity which surrounds the liquid. The air takes some time for this warm air to dissipate into the surrounding. The presence of a breeze, a strong wind, or some other form of air circulation will intensify this process and make the liquid atmosphere less humid.

Therefore, with the increase of surface area, increase of temperature, decrease in humidity and increase in wind speed, the rate of evaporation will increase.
Hence, option A is correct.

Note- Evaporation is a surface phenomenon which means the process occurs only on the liquid surface. It should be noted that the ambient temperature can also lead to faster evaporation, as surrounding conditions being hot may transfer their heat to the liquid. Also, more water vapour will retain hot air than cold air.