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Vapor Pressure of Water Calculator
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Vapor pressure is the minimum amount of pressure that must be applied to a liquid's surface to prevent it from evaporating. In other words it is an indication of a liquids evaporation rate.

Vapor pressure of water (P) = 10A−[B/(C+T)]

Where
• P - Vapor Pressure of Water
• T - Water Temperature, in Celsius
• A,B,C - Antoine Constants for Water. When water temperature in the range of 1-100 Celsius A=8.07131, B=1730.63, C=233.426; when the temperature in the range of 99-374 degree Celsius, A=8.14019, B=1810.94 and C=244.485.

## Steps for Vapor Pressure of Water Calculator

Step 1 :

Read the problem and observe the value of water temperature given.

Step 2 :

Substitute the value of temperature in the formula.

P =10A−[B/(C+T)]

## Problems on Vapor Pressure of Water Calculator

1. ### Calculate the vapor pressure of water at 70oF.

Step 1 :

The temperature of water is given as 70oF. Convert it into centigrade.

70oF = 21.1oC

Step 2 :

Substitute the value in the formula to obtain the vapor pressure of water.

P = 10A−[B/(C+T)]

P = 108.07131 - [1730.63/(233.426+21.1)]

P = 18.701 mmHg

The vapor pressure of water is P = 18.701 mmHg.

2. ### Calculate the vapor pressure of water at 65oF.

Step 1 :

The temperature of water is given as 65oF. Convert it into centigrade.

65oF = 18.3oC

Step 2 :

Substitute the value in the formula to obtain the vapor pressure of water.

P = 10A−[B/(C+T)]

P = 108.07131 - [1730.63/(233.426+18.3)]

P = 15.712 mmHg