A decomposition reaction has a half-life that does not depend on the initial con
ID: 1012534 • Letter: A
Question
A decomposition reaction has a half-life that does not depend on the initial concentration of the reactant. What is the order of the reaction? a) zero order b) first order c) second order d) Order cannot be determined without more information. The rate constant of a reaction is measured at different temperatures. A plot of the natural log of the rate constant as a function of the inverse of the temperature (in kelvins) yields a straight line with a slope of-8.55 X 10^3 K^-1. What is the activation energy (E_a) for the reaction? a) -71 kJ b) 71 kJ c) 1.0 kJ d) -1.0 kJ The rate constant for a reaction at 25.0 degree C is 0.010 s^-1 and its activation energy is 35.8 kJ. Find the rate constant at 50.0 degree C. a) 0.021 s^-l b) 0.010 s^-1 c) 0.0033 s^-1 d) 0.031s^-1 The mechanism shown here is proposed for the gas phase reaction. 2 N_2O_5 rightarrow 2 NO_2 + O2. What rate law does the mechanism predict? a) Rate = k[N_2O_5] b) Rate = k|N_2O_5]^2 c) Rate = [N_2O_5]^0 d) Rate = k[NExplanation / Answer
Q 8 : the reaction wherein, the half life is independent of initial concentration is,
b) First order
Q 9 : For the reaction,
slope = -Ea/R = -(-8.55 x 10^3)
Ea = 8.55 x 10^3 x 8.314
b) 71 kJ
Q 10 : Using,
ln(k2/k1) = Ea/R[1/T1 - 1/T2]
Feeding the values,
ln(k2/0.01) = 35800/8.314 [1/298 - 1/320]
rate constant k2 at 50 oC = 0.031 s-1
d) 0.031 s-1
Q 11 : From the given mechanism, the rate from the slow step is,
d) rate = k[NO2][NO3]
Q 12 : True statement regarding catalyst,
d) all of the above are true