Which statement best rationalizes /\ssys for combustion of methane ch4(g)+2o2(g)→co2(g)+2h2o(g) a. there is a combustion reaction, so /\ssys will be a large negative number.
b. there are no changes os state and no change in nrxn so /\ssys will be small
c. combustion reactions are exothermic, so /\ssys also will be a large negative number
d. this is a combustion reaction so /\ssys will be a large positive number

Ithink d hope that

Reaction involved in present system is :   c12h22o11 + h2o → 2 c6h12o6the reaction system is obeying following rate law:   rate = k[c12h22o11]thus, it is a first order reaction.now, for 1st order reactionrate constant (k) =  given: initial conc. = 3.0 g, final conc. = 2.7 g, t = 2.5 h∴rate constant (k) =  ∴ k = 0.04215 h-1now, for 1st order reaction, half life = 0.693/k = 0.693/0.04215 = 16.4 hthus correct answer is option b