Advertisements
Advertisements
Question
The rate constant of the first order reaction is 1.386 min–1. Calculate the time required for 80% reactant to decompose?
Advertisements
Solution
Given: [A]0 = 100%, k = 1.386 min–1
To find: Time required for 80% reactant to decompose
Formula: t = `2.303/"k" log_10 ["A"]_"o"/["A"]_"t"`
Calculations: The reactant is 80% decomposed. Hence, [A]t = 20%.
t = `2.303/"k" log_10 ["A"]_"o"/["A"]_"t"`
Substituting the values,
t = `2.303/(1.386 "min"^-1) log_10 100/20`
= `2.303/(1.386 "min"^-1) xx 0.69897`
= 1.16 min × `(60 "s")/(1 "min")`
= 69.6 s
Time required for reducing concentration of reactant to 20 % is 1.16 min or 69.6 s.
APPEARS IN
RELATED QUESTIONS
Answer the following in one or two sentences.
Write the relationships between rate constant and half-life of the first order and zeroth-order reactions.
Answer the following in brief.
Derive the integrated rate law for the first-order reaction.
How will you represent first order reactions graphically.
Solve
A first-order reaction takes 40 minutes for 30% decomposition. Calculate its half-life.
Answer the following in brief.
Give one example and explain why it is pseudo-first-order.
For first order reaction, the rate constant for the decomposition of N2O5 is 6 × 10–4 s –1. The half-life period for decomposition in seconds is ______.
Write a mathematical expression for integrated rate law for zero-order reaction.
Derive an integrated rate law expression for first order reaction: A → B + C
Write units of rate constants for:
- First-order reaction
- Zero-order reaction
For a first-order reaction, the rate constant is 6.909 min−1 the time taken for 75% conversion in minutes is
Assertion: rate of reaction doubles when the concentration of the reactant is doubles if it is a first-order reaction.
Reason: rate constant also doubles.
Write the rate law for the following reaction.
A reaction that is second order in NO and first order in Br2.
A zero order reaction is 20% complete in 20 minutes. Calculate the value of the rate constant. In what time will the reaction be 80% complete?
What is the value of rate constant of first order reaction, if it takes 15 minutes for consumption of 20% of reactants?
How long would it take to electroplate a spoon with 0.1 mol of silver (108 g/mol) at a constant current of 2.0 A using AgNO3?
The time of completion of 90% of a first order reaction is approximately ____________.
The rate constant of a reaction has same units as the rate of reaction. The reaction is of ____________.
A first order reaction completes its 10% in 20 minutes, then the time required to complete its 19% is ____________.
In a first order reaction, the concentration of the reactant, decreases from 0.8 mol dm−3 to 0.4 mol dm−3 in 15 minutes. The time taken for the concentration to change from 0.1 mol dm−3 to 0.025 mol dm−3 is ____________.
For a zero order reaction, the plot of [A]t vs t is linear. The slope of the line is equal to ____________.
The rate of formation of B at time t for reaction \[\ce{2A -> 3B}\] is equal to ____________.
For a first order reaction, \[\ce{A -> B}\], if [A] = 1 M and rate is 4 × 10−2 M s−1. What is the rate constant of the reaction?
A first order reaction is 50% completed in 16 minutes. The percentage of reactant that will react in 32 minutes is ____________.
Half-life of first-order reaction \[\ce{X -> Y + Z}\] is 3 minutes. What is the time required to reduce the concentration of 'X' by 90 % of it's initial concentration?
The rate constant for a first order reaction is 7.0 × 10-4 s-1. If initial concentration of reactant is 0.080 M, what is the half-life of reaction?
Consider the following reaction.
\[\ce{SO2(g) + 1/2 O2(g) <=>[K1] SO3(g)}\]
\[\ce{2SO3(g)<=>[K2] 2SO2(g) + O2(g)}\]
What is the relation between K1 and K2?
A radioactive isotope decayed to 17/32 of its original mass after 60 minutes. Find the half-life of this radioisotope.
What is the rate constant of a first order reaction if 0.08 mole of reactant reduces to 0.02 mole in 23.03 minutes?
The half-life period for the first order reaction is 1.7 hrs. How long will it take for 20% of the reactant to disappear?
Which of the following equations exhibits the integrated rate law equation for first order reaction?
