Which one is not correct mathematical equation for Dalton's law of partial pressure? Here p = total pressure of gaseous mixture
(1) pi = χip, where
Pi = partial pressure of ith gas, χi = mole fraction of ith gas in gaseous mixture
(2) pi = χipi°, where
χi = mole fraction of ith gas in gaseous mixture, pi° = pressure of ith gas in pure state
(3) p = p1 + p2 + p3
(4) $p = n_1{RT\over V}+n_2{RT\over V}+n_3{RT\over V}$