Q. No.Which of the following statements is not correct about the order of a reaction?
| 1. | The order of a reaction can be a fractional number |
| 2. | Order of a reaction is experimentally determined quantity |
| 3. | The order of a reaction is always equal to the sum of the stoichiometric coefficients of reactants in the balanced chemical equation for a reaction |
| 4. | The order of a reaction is the sum of the powers of the molar concentration of the reactants in the rate law expression |
Subtopic: Order, Molecularity and Mechanism |
85%
Level 1: 80%+
Hints
Consider the two rate laws:
(I) Rate = k [A]1/2 [B]3/2
(II) Rate = k [A]3/2 [B]–1
The correct statement among the following is-
| 1. | The overall order for rate expression (I) is 2 and for (II) is \(\frac{5}{2}\) |
| 2. | The overall order for rate expression (I) is 2 and for (II) is \(\frac{1}{2}\) |
| 3. | The overall order for rate expression (I) is -2 and for (II) is \(\frac{3}{2}\) |
| 4. | The overall order for rate expression (I) is -2 and for (II) is \(\frac{5}{2}\) |
Subtopic: Order, Molecularity and Mechanism |
92%
Level 1: 80%+
Hints
Select the correct option based on statements below:
| Assertion (A): | Order and molecularity are the same. |
| Reason (R): | Order is determined experimentally, and molecularity is the sum of the stoichiometric coefficient of the rate-determining the elementary step. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
Subtopic: Order, Molecularity and Mechanism |
79%
Level 2: 60%+
Hints
Links
The correct statements among the following regarding any unimolecular reaction are-
| (a) | Only one reacting species is involved in the rate-determining step |
| (b) | The order and the molecularity of the slowest step are equal to one |
| (c) | The molecularity of the reaction is one and the order is zero |
| (d) | Both molecularity and order of the reaction are one |
| 1. | (a, b) | 2. | (b, c) |
| 3. | (c, d) | 4. | (a, d) |
Subtopic: Order, Molecularity and Mechanism |
55%
Level 3: 35%-60%
Hints
The correct statements among the following regarding a complex reaction are-
| (a) | Order of the overall reaction is the same as the molecularity of the slowest step. |
| (b) | Order of the overall reaction is less than the molecularity of the slowest step. |
| (c) | Order of the overall reaction is greater than the molecularity of the slowest step. |
| (d) | The molecularity of the slowest step is never zero or non-integer. |
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)
Subtopic: Order, Molecularity and Mechanism |
75%
Level 2: 60%+
Hints
Match the items of Column I with items of Column II
| Column I (Concepts Related to Chemical Kinetics) |
Column II (Related Terms) |
||
| A. | Mathematical expression for the rate of reaction | I. | Rate constant |
| B. | Rate of reaction for zero-order reaction is equal to | II. | Rate law |
| C. | Units of rate constant for zero-order reaction is same as that of | III. | Order of slowest step |
| D. | Order of a complex reaction is determined by | IV. | Rate of reaction |
Codes:
| A | B | C | D | |
| 1. | III | IV | I | II |
| 2. | I | II | III | IV |
| 3. | II | I | IV | III |
| 4. | IV | I | III | II |
Subtopic: Order, Molecularity and Mechanism |
86%
Level 1: 80%+
Hints
Links
Select the correct option based on statements below:
| Assertion (A): | The order of the reaction can be zero or fractional. |
| Reason (R): | We cannot determine order from the balanced chemical equation. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
Subtopic: Order, Molecularity and Mechanism |
61%
Level 2: 60%+
Hints
Links
For a certain reaction, the rate = \(k[A]^2[B],\) when the initial concentration of A is tripled keeping the concentration of B constant, the initial rate would be:
| 1. | Increase by a factor of three |
| 2. | Decrease by a factor of nine |
| 3. | Increase by a factor of six |
| 4. | Increase by a factor of nine |
Subtopic: Order, Molecularity and Mechanism |
79%
Level 2: 60%+
NEET - 2023
Hints
For a reaction, A + B → Product; the rate law is given by, r=k[A]1/2[B]2. The order of the reaction is:
| 1. | –1.5 | 2. | 1.5 |
| 3. | 0.5 | 4. | 2.5 |
Subtopic: Order, Molecularity and Mechanism |
79%
Level 2: 60%+
Hints
The conversion of molecules X to Y follows second order kinetics. If concentration of X is increased to three times, then the rate of formation of Y will -
| 1. | Decreases by 3 times | 2. | Increase by 3 times |
| 3. | Decreases by 9 times | 4. | Increase by 9 times |
Subtopic: Order, Molecularity and Mechanism |
77%
Level 2: 60%+
Hints
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