3. What will be the total pressure of the gaseous mixture at equilibrium if \( AB _{2} \) is \( 20 \% \) dissociated according to the following reaction, \( AB _{2}( g ) \rightleftharpoons A ( g )+2 B ( g ) \) ? ( \( K _{ p } \) represents the equilibrium constant of the reaction)
[NCERT Pg. 207]
(1) \( 4 K_{p} \)
(2) \( 7 K_{p}^{1 / 2} \)
(3) \( 2 K_{p}^{1 / 2} \)
(4) \( 3 K_{p}^{1 / 2} \)