according to ideal gas equation , we have
PV = n RT
where P = pressure , V = Volume , n = number of moles , R = gas constant and
T = temperature
the formula can be rearranged as
T = PV/(nR)
at constant temperature , the formula can be reformed as
T₁ = T₂
P₁V₁/(nR) = P₂V₂/(nR)
hence
P₁V₁ = P₂V₂
where
P₁ = initial pressure
P₂ = final pressure = 2 P₁
V₁ = initial volume
V₂ = final volume
P₁V₁ = (2 P₁ )V₂
V₁ = (2) V₂
V₂ = V₁ /2
hence the Volume is halved
