Table of Contents
What is Partial Pressure?
Partial Pressure is the pressure exerted by a gas in a mixture of gases. Dalton’s Law of Partial Pressure states that the total pressure exerted by a mixture of gases is the sum of the pressures that each gas would exert if it were present alone. Mole fraction is the ratio of the number of moles of a particular gas to the total number of moles in the mixture. Partial pressure is calculated by multiplying the mole fraction by the gas’s partial pressure in atmospheres. Partial pressure can be used to calculate the concentration of a gas in a mixture.
Partial pressure:= (mole fraction of gas) x (partial pressure of gas)
Summary in Tabular Form:
- Gas A Gas B Gas C
- Mole fraction 0.5 0.3 0.2
- partial pressure 2 atm 1 atm 0.5 atm
- Total pressure 3 atm 2 atm 1 atm
In chemistry, partial pressure is the pressure of a gas relative to the total pressure of a mixture of gases. It is calculated by dividing the gas pressure by the total gas pressure. Partial pressure is important in gas laws, and it is also used in gas chromatography and other separation techniques.
Dalton’s Law of Partial Pressure
Dalton’s law of partial pressure states that the total pressure of a gas mixture is equal to the sum of the partial pressures of the component gases. In other words, the pressure that each gas in a mixture would exert if it were present alone is what it actually contributes to the total pressure. This is true for all gases, regardless of whether or not they react with each other.
The law is named after English chemist John Dalton, who first proposed it in 1801. It is one of the gas laws, which describe the behavior of gases under different conditions. The others are Boyle’s law, Charles’ law, and the Ideal Gas law.
Dalton’s law is important in many fields, including atmospheric science, meteorology, and engineering. It is used to calculate the partial pressure of each gas in a mixture, which is necessary for many calculations. For example, it is used to determine the partial pressure of oxygen in air, which is important for respiratory physiology.
The law can be stated mathematically as follows:
Ptotal = P1 + P2 + … + Pn
where Ptotal is the total pressure of the gas mixture, and P1, P2, …, Pn are the partial pressures of the component gases.
