Question

Rate of evaporation increases with increase in surface area, but not vapour pressure. Why?

Answer 1

Hi there!

As the surface area increases, more number of molecules will escape per unit time.

Therefore, rate of evaporation increases.

But vapour pressure in nothing but pressure and is defined as force per unit area.

Hope it helps!

Answer 2

Hey......!!!! :)) ✌️✌️

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=> Rate of evaporation:-

A substance that has a larger surface area will evaporate faster, as there are more surface molecules per unit of volume that are potentially able to escape. the higher the temperature of the substance the greater the kinetic energy of the molecules at its surface and therefore the faster the rate of their evaporation.


Evaporation formula:-

E= 7.4 PA ( 0.447W) ^0.78
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T + 459.67

Where:

E = Evaporation Rate (Gallons/Day)

A = Pool Surface Area (ft2)

W = Wind Speed Above Pool (mph)

P = Water's Vapor Pressure (mmHG) at Ambient Temperature

T = Temperature (°F)

Factor of increased evaporation rate:-

<> Surface area: The rate of evaporation increases with an increase in surface area.

<> Temperature :- The rate of evaporation increases with an increase in temperature. Surface area: The rate ofevaporation increases with anincrease in surface area. Humidity: The amount of water vapour present in the air is called humidity. The rate ofevaporation decreases with anincrease in humidity .

<> Air currents,:- if the air is moving (wind, breeze) the water vapour that forms above the water surface will be carried away preventing the air above the water surface from reaching 100% humidity, preventing equilibrium from being established, allowing water to continue to evaporate.

<> Humidity:- If water evaporates in an air-tight container, the space above the water is filled with more and more water vapour. When the air contains a lot of water vapour, humidity is high.

Surface area :- Rate of evaporation" depends on surface area because the bigger the area the more liquid is available to evaporate. Also, "vapour pressure" is indeed caused by the evaporation of the liquid. However, it's defined as the equilibrium pressure reached in a closed container. 

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I hope it's help you....!!! :)) ✌️✌️