**Gas Equation**

source :theyoungscottishphysicist.co.uk

According to Boyle’s law

V ∝ 1/P (T is constant)

According to Charle’s Law

V ∝ T (P is constant)

Combining these two laws,

V ∝ T/P

PV ∝ T

PV = KT

PV/T = constant

K is a constant

For one mole of gas, the constant K is replaced by R. Since the value of R is same for each gas, it is known as universal gas constant

PV = RT ———gas eq.

P=Pressure of gas

V= Vol. of 1 mole of gas

T= Temperature in Kelvin (Absolute Temp.)

R= Universal gas constant

Gas Eq. for n mole of gas,

PV =nRT ( Gas equ. )

n= no. of moles of Gas

Above gas eq. may be written as,

n = w/m

PV = w/m (RT) ——–gas equation

w=weight or mass in grams

m=molecular weight of gas

density of gas d = w/v

P = DRT/m gas equ.