Advertisements
Advertisements
प्रश्न
What is pseudo first order reaction? Give one· example of it.
Advertisements
उत्तर
A reaction which has higher order true rate law but experimentally found to behave as first order are called pseudo first order reaction.
e.g. `C_12H_22O_(11(aq))+H_2OrarrC_6H_12O_6+C_6H_12O_6`
Sucrose Glucose fractose
is an example of pseudo first order reaction, because water takes part in the reaction the true rate law
rate = k'[C12H22O11][H2O]
indicates that the reaction must be second order. Similarly to the hydrolysis of ester,[H2O] is constant and
the rate law became
rate=k[C12H22O11]
Thus, the second order true law is converted, to first order rate law.
APPEARS IN
संबंधित प्रश्न
Define “zero order reaction”.
For the first order thermal decomposition reaction, the following data were obtained:
Time / sec Totalpressure / atm
0 0.30
300 0.50
Calculate the rate constant
(Given: log 2 = 0.301, log3 = 0.4771, log 4 = 0.6021)
Write two factors that affect the rate of reaction.
For a reaction A + B ⟶ P, the rate is given by
Rate = k [A] [B]2
How is the rate of reaction affected if the concentration of B is doubled?
For a reaction A + B ⟶ P, the rate is given by
Rate = k [A] [B]2
What is the overall order of reaction if A is present in large excess?
For a reaction, \[\ce{A + B -> Product}\]; the rate law is given by, r = k [A]1/2 [B]2. What is the order of the reaction?
From the rate expression for the following reaction, determine the order of reaction and the dimension of the rate constant.
\[\ce{3NO_{(g)} -> N2O_{(g)}}\] Rate = k[NO]2
From the rate expression for the following reaction, determine the order of reaction and the dimension of the rate constant.
\[\ce{H2O2_{( aq)} + 3I^-_{( aq)} + 2H^+ -> 2H2O_{(l)} + I^-_3}\] Rate = k[H2O2][I−]
For the reaction:
\[\ce{2A + B -> A2B}\]
the rate = k[A][B]2 with k = 2.0 × 10−6 mol−2 L2 s−1. Calculate the initial rate of the reaction when [A] = 0.1 mol L−1, [B] = 0.2 mol L−1. Calculate the rate of reaction after [A] is reduced to 0.06 mol L−1.
A reaction is first order in A and second order in B. Write the differential rate equation.
For a reaction R ---> P, half-life (t1/2) is observed to be independent of the initial concentration of reactants. What is the order of reaction?
Which of the following statements is not correct about order of a reaction.
Consider the reaction A ⇌ B. The concentration of both the reactants and the products varies exponentially with time. Which of the following figures correctly describes the change in concentration of reactants and products with time?
In a reaction if the concentration of reactant A is tripled, the rate of reaction becomes twenty seven times. What is the order of the reaction?
Why can we not determine the order of a reaction by taking into consideration the balanced chemical equation?
Assertion: Order and molecularity are same.
Reason: Order is determined experimentally and molecularity is the sum of the stoichiometric coefficient of rate determining elementary step.
Assertion: The enthalpy of reaction remains constant in the presence of a catalyst.
Reason: A catalyst participating in the reaction, forms different activated complex and lowers down the activation energy but the difference in energy of reactant and product remains the same.
For a reaction R → p the concentration of reactant change from 0.03 m to 0.02 m in minute, calculate the average rate of the reaction using the unit of second.
For a reaction \[\ce{Cl2l(g) + 2No(g) -> 2NaCl(g)}\] the rate law is expressed as rate= K[Cl2] [No]2 what is the order of the reaction?
If the 0.05 molar solution of m+ is replaced by a 0.0025 molar m+ solution, then the magnitude of the cell potential would be
For a reaction 1/2 A ⇒ 2B, rate of disappearance of A is related 't o the appearance of B by the expression:
The half-life period of a. substance in a certain enzyme catalysed reaction is 138 s. The time required for the concentration of the substance to fall from 1.28 mol–1 to 0.04 mg L–1 is
For the reaction, \[\ce{A +2B → AB2}\], the order w.r.t. reactant A is 2 and w.r.t. reactant B. What will be change in rate of reaction if the concentration of A is doubled and B is halved?
Identify the order of reaction from the following unit for its rate constant:
L mol–1 s–1
For a chemical reaction starting with some initial concentration of reactant At as a function of time (t) is given by the equation,
`1/("A"_"t"^4) = 2 + 1.5 xx 10^-3` t
The rate of disappearance of [A] is ____ × 10-2 M/sec when [A] = 2 M.
[Given: [At] in M and t in sec.]
[Express your answer in terms of 10-2 M /s]
[Round off your answer if required]
A flask contains a mixture of compounds A and B. Both compounds decompose by first-order kinetics. The half-lives for A and B are 300 s and 180 s, respectively. If the concentrations of A and B are equal initially, the time required for the concentration of A to be four times that of B (in s) is ______. (Use ln 2 = 0.693)
Assertion (A): Order of reaction is applicable to elementary as well as complex reactions.
Reason (R): For a complex reaction, molecularity has no meaning.
A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is reduced to half?
