Advertisements
Advertisements
Question
Define order of reaction with suitable examples.
Advertisements
Solution
The order or overall order of the chemical reaction is given as the sum of powers of the concentration terms in the rate law expression.
For the reaction,
aA + bB → cC + dD
If the rate of the reaction is given as
rate = k[A]x [B]y.
Then, the sum x + y gives overall order of the reaction.
e.g. For the reaction
H2(g) + I2(g) → 2HI(g) is
rate = k[H2][I2].
The reaction is of first-order in H2 and I2 each and hence overall order is second order.
For the reaction,
2H2O2(g) → 2H2O(l) + O2(g)
Experimentally determined rate law is rate = k[H2O2].
The reaction is of first-order in H2O2 and hence, the overall order is first order.
APPEARS IN
RELATED QUESTIONS
Choose the most correct option.
The rate constant for the reaction \[\ce{2N2O5_{(g)} -> 2N2O4_{(g)} + O2_{(g)}}\] is `4.98 xx 10^-4 "s"^-1`. The order of reaction is _____________.
The time required for 90% completion of a certain first-order reaction is t. The time required for 99.9% completion will be _________.
Choose the most correct option.
Slope of the graph ln[A]t versus t for first-order reaction is _________.
The elementary reaction \[\ce{O3_{(g)} + O_{(g)} -> 2O2_{(g)}}\] is ______.
Choose the most correct option.
Rate law for the reaction, \[\ce{2NO + Cl2 -> 2NOCl}\] is rate = k[NO2]2[Cl2]. Thus of k would increase with _____________.
Answer the following in one or two sentences.
For the reaction, \[\ce{CH3Br_{(aq)} + OH^{-}_{(aq)} -> CH3OH^{\ominus}_{(aq)} + Br^{\ominus}_{(aq)}}\], rate law is rate = \[\ce{k[CH3Br][OH^\ominus]}\]
How does reaction rate changes if \[\ce{[OH^\ominus]}\] is decreased by a factor of 5?
A First order reaction is 50% complete in 69.3 minutes. Time required for 90% completion for the same reaction is _______.
Order of reaction for which unit of rate constant is mol dm–3 s–1 is _______.
For the reaction \[\ce{2NO_{(g)} + 2H_{2(g)} -> N_{2(g)} + 2H2O_{(g)}}\],
The rate law is, rate = k[NO]2 [H2].
What is the overall order of reaction?
Write four key points about order of reaction.
In a first-order reaction A → B, 60% of a given sample of a compound decomposes in 45 mins. What is the half-life of reaction? Also, write the rate law equation for the above first-order reaction.
In a hypothetical reaction,
\[\ce{2A + B -> Products}\]. Rate = k [A]2 [B]
Molar concentration of 'B' is kept constant and molar concentration of 'A' is tripled, then the rate of reaction will ____________.
A gaseous hypothetical chemical equation \[\ce{2A ⇌ 4B + C}\] is carried out in a closed vessel. The concentration of B is found to increase by 5 × 10−3 mol dm−3 in 10 second. The rate of ____________.
For a chemical reaction rate law is, rate = k[A]2[B]. If [A] is doubled at constant [B], the rate of reaction ______.
For a hypothetical reaction \[\ce{A + B -> C}\], it is found that doubling the concentration of A increases the rate by 8 times and doubling the concentration of B increases the rate by 4 times. The overall order of the reaction is ____________.
The order of the reaction occurring by following mechanism should be:
(i) \[\ce{A2 + B2 -> AB2 + A (slow)}\]
(ii) \[\ce{A + B2 -> AB2 (fast)}\]
Consider the reaction \[\ce{2A + 2B -> C + 2D}\], if concentration of A is doubled at constant [B], rate increases by a factor 4. If concentration B is doubled at constant [A] the rate is doubled. Rate law of the reaction is ____________.
The reaction \[\ce{A + B -> P}\], is second order in A and first order in B. What is the rate law for the reaction?
What is the order of reaction for decomposition of gaseous acetaldehyde?
What is the molecularity and order of the following reaction if rate law is, rate = k[O3][O] respectively.
\[\ce{O_{3(g)} + O_{(g)} -> 2O_{2(g)}}\]
For the reaction \[\ce{4NH3 + 5O2 -> 4NO + 6H2O}\], the rate of disappearance of NH3 is 3.6 × 10-3 M/s. What is the rate of formation of water?
Write the rate law for the following reaction:
A reaction that is zero order in A and second order in B.
The rate constant of a reaction ______.
The rate constant for the reaction,
2N2O5(g) → 2N2O4(g) + O2(g) is 4.98 × 10-4 s-1.
What is the order of reaction?
`t_(1/4)` can be taken as the time taken for the concentration of a reactant to drop to `3/4` of its initial value. If the rate constant for a first order reaction is k, the `t_(1/4)` can be written as ______.
