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

# Dalton's Law

## Gibbs' Dalton's law of the total pressure of a mixture of gases.

The total pressure of a mixture of gases is made up by the sum of the partial pressures of the components in the mixture - also known from Gibbs'-Dalton's Law of Partial Pressures.

• the total pressure exerted by a mixture of gases is the sum of the partial pressures of the individual gases

The total pressure in a mixture of gases can be expressed as:

p total = p1 + p2+ .. + p n

= Σp i (1)

where

p total = total pressure of mixture    (Pa, psi)

p i = partial pressure of individual gas   (Pa, psi)

Assuming that each gas behaves ideally - the partial pressure for each gas can calculated from the Ideal gas Law as

p i = n1 R T / V                     (2)

where

p i = pressure (Pa, psi)

n1 = the number of moles of the gas

R = universal gas constant (J/(mol K), lbf ft/(lb mol o R),  8.3145 (J/(mol K))

T = absolute temperature (K, o R)

V = volume (m3, ft3 )

### Example - Partial Pressure of single Gas

If there is 2 moles of gas in 0.005 m3 volume ( 5 litre ) with temperature 27°C ( 300 K ) - the partial pressure of the gas can be calculated as

p i = (2) ( 8.3145 J/(mol K) ) (300 K) / (0.005 m3 )

= 997740 Pa

= 997 kPa

## Related Topics

• ### Gases and Compressed Air

Properties of air, LNG, LPG and other common gases. Pipeline capacities and sizing of relief valves.

## Related Documents

• ### Air and Steam Mixtures

Air in the steam will lower the surface temperatures in heat exchangers - and less heat will be transferred.
• ### Carnot Efficiency

The efficiency of the Carnot cycle.

## Search

Search is the most efficient way to navigate the Engineering ToolBox.

## 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 older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .

## Citation

• The Engineering ToolBox (2008). Dalton's Law. [online] Available at: https://www.engineeringtoolbox.com/daltons-law-d_1052.html [Accessed Day Month Year].

Modify the access date according your visit.

7.25.9

.