Advertisements
Advertisements
प्रश्न
With the help of an example explain what is meant by pseudo first order reaction.
Advertisements
उत्तर
Pseudo first order reaction: Reaction which appears to be a second order reaction, but actually is first order reaction is called pseudo first order reaction. This condition occurs in a chemical reaction between two substances when one reactant is present in large amount. The concentration of reactant present in excess does not gat alterned much during the course of the reaction. Due to this reaction behaves as first order reaction.
E.g. hydrolysis of esters
\[\ce{CH3COOC2H5 + H2O -> CH3COOH + C2H5OH}\]
Rate law for this reaction is; rate = \[\ce{k[CH3COOC2H5]][H2O]}\]
But the concentration of water does not change during the course of the reaction. So; \[\ce{H2O}\] is constant.
Therefore rate = \[\ce{k1[CH3COOC2H5]}\], where \[\ce{k = k[H2O]}\].
The reaction behaves as a first order reaction.
APPEARS IN
संबंधित प्रश्न
Sucrose decomposes in acid solution into glucose and fructose according to the first order rate law with `t_(1/2)` = 3 hours. What fraction of the sample of sucrose remains after 8 hours?
A first order reaction has a rate constant 1.15 × 10−3 s−1. How long will 5 g of this reactant take to reduce to 3 g?
A first order reaction takes 20 minutes for 25% decomposition. Calculate the time when 75% of the reaction will be completed.
(Given : log = 2 = 0·3010, log 3 = 0·4771, log 4 = 0·6021)
Define order of reaction. How does order of a reaction differ from molecularity for a complex reaction?
A first order reaction is 50% complete in 25 minutes. Calculate the time for 80% completion of the reaction.
Straight line graph for first order reaction is obtained between ____________.
In the presence of acid, the initial concentration of cane sugar was reduced from 0.2 M to 0.1 Min 5 hours and to 0.05 Min 10 hours. The reaction must be of?
The rate constant of a first order reaction is 6.9 × 10–3s–1. How much time will it take to reduce the initial concentration to its 1/8th value?
A first order reaction is 50% complete in 20 minute What is rate constant?
Time required to decompose SO2Cl2 to half of its initial concentration is 60 minutes. If the de-composite is a first order reaction, calculated the rate constant of the reaction-
The reaction \[\ce{SO2Cl2(g) -> SO2(g) + Cl2(g)}\] is a first-order gas reaction with k = 2.2 × 10−5 sec−1 at 320°C. The percentage of SO2Cl2 is decomposed on heating this gas for 90 min, is ______%.
The slope in the plot of ln[R] vs. time for a first order reaction is ______.
The slope in the plot of `log ["R"]_0/(["R"])` Vs. time for a first-order reaction is ______.
How will you represent first order reactions graphically?
What is the rate constant?
The following data were obtained during the decomposition of SO2Cl2 at the constant volume. SO2Cl2 →SO2(g) + Cl2(g)
| Time (s) | Total Pressure (bar) |
| 0 | 0.5 |
| 100 | 0.6 |
Calculate the rate constant of the reaction.
Slove: \[\ce{2NOBr -> 2NO_{2(g)} + Br_{2(g)}}\]
For the above reaction, the rate law is rate = k[NOBr]2. If the rate of reaction is 6.5 × 10−6 mol L−1 s−1 at 2 × 10−3 mol L−1 concentration of NOBr, calculate the rate constant k for the reaction.
The rate constant for the reaction:
\[\ce{2N2O_{(s)} ->2N2O4_{(g)}}\] is 4.98 × 10-4 s-1.
The order of the reaction is ______.
Write the equation for integrated rate law for a first order reaction.
