The following gas phase reaction is second order. 2C2H4(g)--->C4H8(g) Its half life is 1.51 min when [C2H4] is 0.250 M. a.What is k for the reaction? b.How long will it take to go from 0.187 M to 0.0915 M? c.What is the rate of the reaction when [C2H4] is 0.335M?