# Daltons Law of Partial Pressure | chemistry Grade XI |

Note credit : pooja bhatta

Partial Pressure : The  Pressure exerted by gas due to the striking of the gas molecule on the wall of the container it depends upon the number of molecule.

The pressure exerted by individual gas is the mixture of two  or more  non- reacting gases is called partial pressure.

## Dalton’s law of partial pressure;

It states that ” The total pressure exerted by gases mixture  of two  or more non-reacting gases is equal o the sum of partial pressure of the component of gases at constant temperature.

Mathemathically,

Pt = P1 + P2 + P3 ————–Pn

where p1,, p2,,,, p3,,, pn are the partial pressure of component of gases and pT is the total pressure of gaseous mixture.

## Mathemathical deduction of dalton law of partial pressure by ideal ideal gas equation

Let, three gases A, B and C with Na, Nb, and Nc moles are mixed together in a vessel of volume  “V” constant temperature. If partial pressure of gases are Pa, Pb, and Pc respectively  and the total pressure is Pt. thus ideal eqution can be applied for the calculation of partial pressure of component of gases.

for ideal gas equation,

PV=nRt
P = NRT/V …………………… (?)
There fore, partial pressure of gas is
Pa= NaRT/V ………………………………… (ii)
Pb=NbRT/V …………………………………(iii)
Pc=NcRT/V

Where

PT =  total pressure of gaseous mixture
NT= Total number of moles of gases
v= total number of gas constant