Integrated rate equations and half-life (zero and first order)

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If the rate constant of a reaction is 0.03 s^-1, how much time does it take for 7.2 mol L^-1 concentration of the reactant to get reduced to 0.9 mol L^-1?(Given: log 2 = 0.301) Answer: 1. 69.3 s Key idea: the unit mathrms⁻¹ means first order: t=2.303/klog[A]₀/[A] . 7.2/0.9=8 , log8=3×0.301=0.903 . t=2.303×0.903/0.03... Integrated rate equations and half-life (zero and first order) 1 answer
If the half-life (t_1/2) for a first order reaction is 1 minute, then the time required for 99.9% completion of the reaction is closest to : Answer: 4. 10 minutes Key idea: first order: k=frac0.693t_(1/2) and t=2.303/kloga/a-x . k=0.693\ mathrmmin⁻¹ . 99.9% complete: a/a-x=1000 ,... Integrated rate equations and half-life (zero and first order) 1 answer
For a first order reaction A → Products, initial concentration of A is 0.1 M, which becomes 0.001 M after 5 minutes. Rate constant for the reaction in min^-1 is Answer: 3. 0.9212 Key idea: for a first order reaction k=2.303/tlog[A]₀/[A] . k=2.303/5log0.1/0.001=2.303/5×2=0.9212\ mathrmmin⁻¹ . Integrated rate equations and half-life (zero and first order) 1 answer
The given graph is a representation of kinetics of a reaction.[Graph: y versus x at constant temperature T]The y and x axes for zero and first order reactions, respectively are Answer: 4. zero order ( y = rate and x = concentration), first order ( y = t_(1/2) and x = concenration) Key idea: a horizontal line means y... Integrated rate equations and half-life (zero and first order) 1 answer
The rate constant for a first order reaction is 4.606×10^-3 s^-1. The time required to reduce 2.0 g of the reactant to 0.2 g is : Answer: 3. 500 s For a first-order reaction t=2.303/klog[A]₀/[A] . t=frac2.3034.606×10⁻³log2.0/0.2=frac2.3034.606×10⁻³×1=500\ s Answer: opti... Integrated rate equations and half-life (zero and first order) 1 answer
If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by : Answer: 3. t = 4.606/k For a first order reaction t = 2.303/klog[A]₀/[A] . When 99% is complete, [A] = 0.01[A]₀ , so t = 2.303/klog 100 = 2.... Integrated rate equations and half-life (zero and first order) 1 answer
The correct difference between first- and second-order reactions is that Answer: 3. the half-life of a first-order reaction does not depend on [A] ₀ ; the half-life of a second-order reaction does depend on [A] ₀... Integrated rate equations and half-life (zero and first order) 1 answer
When initial concentration of the reactant is doubled, the half-life period of a zero order reaction Answer: 3. is doubled For a zero-order reaction, t_(1/2)=[A]₀/2k , directly proportional to the initial concentration. If [A]₀ is doubled, t... Integrated rate equations and half-life (zero and first order) 1 answer
A first order reaction has a specific reaction rate of 10^-2\ sec^-1. How much time will it take for 20 g of the reactant to reduce to 5 g ? Answer: 1. 138.6 sec Key idea: first-order integrated rate law t=2.303/kloga/a-x . t=dfrac2.30310⁻²log20/5=230.3×0.602=138.6\ s . Check: 20... Integrated rate equations and half-life (zero and first order) 1 answer
The rate of a first-order reaction is 0.04\ mol\ l^-1\ s^-1 at 10 seconds and 0.03\ mol\ l^-1\ s^-1 at 20 seconds after initiation of the reaction. The half-life period of the reaction is : Answer: 1. 24.1 s Key idea: for a first-order reaction, rate = k[A] , so the ratio of rates equals the ratio of concentrations. [A]₁₀/[A]₂₀=... Integrated rate equations and half-life (zero and first order) 1 answer