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प्रश्न
Mention the factors that affect the rate of a chemical reaction.
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उत्तर
The factors that affect the rate of a reaction are as follows:
(i) Nature of the reactant - The rate of reaction depends on the nature of the reactant. For instance, ionic molecules react more quickly than covalent ones.
(ii) State of reactants - Solid reactions are slower, liquid reactions are faster, and gas reactions are very quick.
(iii) Temperature - The rate of reaction is mainly affected by temperature. Every 10°C rise in temperature leads to an increased rate of reaction by 2-3 times.
`(r_(t + 10))/r_t` = 2 − 3
This ratio is called the temperature coefficient.
There are two reasons why the rate of reaction increases with increasing temperature.
- Increasing temperature raises the average kinetic energy of reactant molecules, increasing the rate of collisions.
- As temperature rises, the number of molecules with threshold energy increases, resulting in more active molecules. As a result, the number of effective collisions grows. As a result, the rate of reaction rises.
(iv) Concentration - The rate of reaction depends on the concentration of reactants.
Rate = k × Cn, where n = order of reaction, C = concentration of reactant.
(v) Catalyst - The presence of a catalyst changes the rate of the reaction. It lowers the activation energy by producing a chemical intermediate, lowering the potential energy barrier. Thus, the rate of reaction increases.
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संबंधित प्रश्न
In a first order reaction x → y, 40% of the given sample of compound remains unreacted in 45 minutes. Calculate rate constant of the reaction.
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 : 
(i) Write the order and molecularity of this reaction.
(ii) Write the unit of k.
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?
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 statement is true for order of a reaction?
Compounds ‘A’ and ‘B’ react according to the following chemical equation.
\[\ce{A(g) + 2B(g) -> 2C(g)}\]
Concentration of either ‘A’ or ‘B’ were changed keeping the concentrations of one of the reactants constant and rates were measured as a function of initial concentration. Following results were obtained. Choose the correct option for the rate equations for this reaction.
| Experiment | Initial concentration of [A]/mol L–¹ |
Initial concentration of [B]/mol L–¹ |
Initial rate of formation of [C]/mol L–¹ s–¹ |
| 1. | 0.30 | 0.30 | 0.10 |
| 2. | 0.30 | 0.60 | 0.40 |
| 3. | 0.60 | 0.30 | 0.20 |
The value of rate constant of a pseudo first order reaction ______.
In any unimolecular reaction:
(i) only one reacting species is involved in the rate determining step.
(ii) the order and the molecularity of slowest step are equal to one.
(iii) the molecularity of the reaction is one and order is zero.
(iv) both molecularity and order of the reaction are one.
For a complex reaction:
(i) order of overall reaction is same as molecularity of the slowest step.
(ii) order of overall reaction is less than the molecularity of the slowest step.
(iii) order of overall reaction is greater than molecularity of the slowest step.
(iv) molecularity of the slowest step is never zero or non interger.
Why molecularity is applicable only for elementary reactions and order is applicable for elementary as well as complex reactions?
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 first order A → B, the reaction rate at reactant concentration of 0.01 m is found to be 2.0 × 10–5. The half-life period of reaction.
The rate of a chemical reaction double for every 10° rise in temperature. If the temperature is raised. by 50°C, the rate of relation by about:-
The number of molecules of the reactants taking part in a single step of the reaction is indicative of ______.
Identify the order of reaction from the following unit for its rate constant:
L mol–1 s–1
The following data was obtained for chemical reaction given below at 975 K.
\[\ce{2NO(g) + 2H2(g) -> N2(g) + 2H2O(g)}\]
| [NO] | [H2] | Rate | |
| Mol L-1 | Mol L-1 | Mol L-1 s-1 | |
| (1) | 8 × 10-5 | 8 × 10-5 | 7 × 10-9 |
| (2) | 24 × 10-5 | 8 × 10-5 | 2.1 × 10-8 |
| (3) | 24 × 10-5 | 32 × 10-5 | 8.4 × 10-8 |
The order of the reaction with respect to NO is ______. (Integer answer)
Assertion (A): Order of reaction is applicable to elementary as well as complex reactions.
Reason (R): For a complex reaction, molecularity has no meaning.
