What is true regarding reactions that consist of a multistep mechanism?
A.
The rate of the overall reaction is faster than the slowest step.
B.
The rate of the overall reaction is slower than the slowest step.
C.
The rate of the overall reaction is equal to the fastest step.
D.
The rate of the overall reaction is the average of the rates of all elementary steps.

The formula is (nh4)2co3

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