Dilution (equation)

Dilution is the process of decreasing the concentration of a

Mathematically this relationship can be shown by equation:

$${\displaystyle c_{1}V_{1}=c_{2}V_{2}}$$

where

• c₁ = initial concentration or molarity
• V₁ = initial volume
• c₂ = final concentration or molarity
• V₂ = final volume

....

Basic room purge equation

The basic room purge equation is used in

concentration in a room.

$${\displaystyle D_{t}=\left[{\frac {V}{Q}}\right]\cdot \ln \left[{\frac {C_{\text{initial}}}{C_{\text{ending}}}}\right]}$$

Sometimes the equation is also written as:

$${\displaystyle \ln \left[{\frac {C_{\text{ending}}}{C_{\text{initial}}}}\right]\quad ={-}{\frac {Q}{V}}\cdot (t_{\text{ending}}-t_{\text{initial}})}$$

where ${\displaystyle t_{\text{initial}}=0}$

• D_t = time required; the unit of time used is the same as is used for Q
• V = air or gas volume of the closed space or room in cubic feet, cubic metres or litres
• Q = ventilation rate into or out of the room in
  cubic feet per minute, cubic metres per hour or litres per second
• C_initial = initial concentration of a vapor inside the room measured in
  ppm
• C_final = final reduced concentration of the vapor inside the room in ppm

The basic room purge equation can be used only for purge scenarios. In a scenario where a liquid continuously evaporates from a container in a ventilated room, a differential equation has to be used:

$${\displaystyle {\frac {dC}{dt}}={\frac {G-Q'C}{V}}}$$

where the ventilation rate has been adjusted by a mixing factor K:

$${\displaystyle Q'={\frac {Q}{K}}}$$

• C = concentration of a gas
• G = generation rate
• V = room volume
• Q′ = adjusted ventilation rate of the volume

Welding

The dilution in welding terms is defined as the weight of the base metal melted divided by the total weight of the weld metal. For example, if we have a dilution of 0.40, the fraction of the weld metal that came from the consumable electrode is 0.60.

See also

• Displacement ventilation
• Reaction rate
• Partial molar quantities
• Apparent molar property
• Excess molar quantity
• Heat of dilution

References

External links

• http://pubs.acs.org/doi/abs/10.1021/ja01320a004
• Easy dilution calculator