The half life (in seconds) of a zero order reaction which has an initial reactant concentration of 0.834 m and k value of 5.42 x10^-2 m/s is 7.694 sec
calculation
t 1/2= [Ao]/ 2k
wher Ao = initial concentration and k = constant
t 1/2= 0.834 m/ (2x5.42 x10^-2 m/s)=7.694 sec