Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

This is an AMP page - Open full page! for all features.

• the most efficient way to navigate the Engineering ToolBox!

# Moist Air - Mole Fraction of Water Vapor

The mole fraction of water vapor is the ratio of the number of mole of water vapor in the moist air - to the total number of mole of dry air and water vapor.

The mole fraction of water vapor in moist air can be expressed as

xw = nw / (na + nw)                                            (1)

where

xw = mole fraction of water vapor

nw = mole of water

na = mole of air

## Related Topics

### • Air Psychrometrics

Moist and humid air - psychrometric charts, Mollier diagrams, air-condition temperatures and absolute and relative humidity and moisture content.

## Related Documents

### Air - Composition and Molecular Weight

Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts.

### Air - Molecular Weight and Composition

Dry air is a mixture of gases where the average molecular weight (or molar mass) can be calculated by adding the weight of each component.

### Gases - Molar Specific Heats

Molar specific heats for some common gases at constant volume.

### Moist Air - Water Vapor and Saturation Pressure

Saturation pressure of water vapor in moist air vs. temperature.

### Mole and the Avagadro's Number

The mole is the SI base unit for an amount of a substance.

### Molecular Weight of Substances

Definition and molecular weight (molar mass) of some common substances.

### Saturated Salt Solutions - Controlling Air Humidity

A salt solutions can be used maintain a particular value of relative humidity.

### The Ideal Gas Law

The relationship between volume, pressure, temperature and quantity of a gas, including definition of gas density.

### Universal and Individual Gas Constants

The Universal and Individual Gas Constants in fluid mechanics and thermodynamics. Individual gas constants for the most common gases.

## Search Engineering ToolBox

• the most efficient way to navigate the Engineering ToolBox!

## SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!