Advertisements
Advertisements
Question
Explain with the help of a potential energy diagram that the catalyst increases the rate of the reaction.
Advertisements
Solution
- A catalyst provides alternative pathway associated with lower activation energy.
Potential energy barriers for catalyzed and uncatalyzed reactions - The potential energy diagram compares the potential energy barriers for the catalysed and uncatalysed reactions. The barrier for uncatalysed reaction (Ea) is larger than that for the same reaction in the presence of a catalyst Ea.
- Consider the decomposition of H2O2 in aqueous solution catalysed by I− ions \[\ce{2H2O_{2(l)} ->[I-] 2H2O_{(l)} + O_{2(g)}}\]
At room temperature, the rate of reaction is slower in the absence of catalyst with its activation energy being 76 kJ mol−1. In the presence of catalyst, iodide ion (I−), the reaction is faster since the activation energy decreases to 57 kJ mol−1.
RELATED QUESTIONS
Answer the following in one or two sentences.
How do the half-lives of the first order and zero-order reactions change with the initial concentration of reactants?
Answer the following in brief.
What are the units of the rate constant?
Time required for 100% completion of a zero order reaction is _______.
Rate constant of a reaction is 3.6 × 10–3 s–1. The order of reaction is ______.
The rate of catalysed reaction is large than the uncatalysed reaction as _______.
Write a mathematical expression for integrated rate law for zero-order reaction.
For a first order reaction \[\ce{A ->Product}\] with initial concentration x mol L−1, has a half life period of 2.5 hours. For the same reaction with initial concentration `("x"/2)` mol L−1 the half life is
The decomposition of phosphine (PH3) on tungsten at low pressure is a first-order reaction. It is because the
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.
Describe the graphical representation of first order reaction.
The time for half change in a first order decomposition of a substance A is 60 seconds. Calculate the rate constant. How much of A will be left after 180 seconds?
The rate of the reaction \[\ce{A + B -> C}\] is 3.6 × 10−2 mol dm−3 s−1 when [A] = 0.3 mol dm−3 and [B] = 0.2 mol dm−3. Calculate k if reaction is first order in A and zero order in B.
A first order reaction is 25% completed in 40 minutes. What is the rate constant k tor the reaction?
The time of completion of 90% of a first order reaction is approximately ____________.
For the first order reaction, plot of log10 [A]t against time 't' is a straight line with a negative slope equal to ____________.
The rate and the rate constants of the reaction, \[\ce{A + 2B -> C + D}\] are 8 × 10−3 mol dm−3 s−1 and 2 × 10−3 s−1 respectively. The concentrations of A and B are 4 mol dm−3 each. The overall order of the reaction is ____________.
Half-life period of a first order reaction, \[\ce{A -> product}\] is 3.0 hours. What is the value of rate constant?
The time required to decompose SO2Cl2 to half of it's initial amount is 60 minutes. Calculate rate constant for this first order reaction.
Rate constant for zero order reaction is 2 × 10-2 mol L-1 s-1. If the concentration of the reactant after 25 sec. is 0.5 M, what is the initial concentration of reactant?
Obtain the expression for half-life and rate constant of the first-order reaction.
The rate constant and half-life of a first order reaction are related to each other as ______.
Which of the following is correct for a first-order 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.
A first order reaction takes 10 minute for 30% completion. Find rate constant of the reaction.
