Q.63. Consider the given graph showing variation of reactant concentration with time. Three differen

Q: What is the correct answer for JEE Main Chemistry Q63?

The correct answer is B. Let's analyze the curves: * **Curve 1**: The concentration of reactant [R] decreases linearly with time. This indicates that the rate of reaction is constant and independent of reactant concentration. This is characteristic of a **zero-order reaction** (Rate = k). * **Curve 2 and 3**: The concentration of reactant [R] decreases non-linearly with time, and the rate of decrease slows down as co

Q: Q.63. Consider the given graph showing variation of reactant concentration with time. Three different reactions were started with identical initial concentration of reactants. Which of the following…

The correct answer is B. Let's analyze the curves: * **Curve 1**: The concentration of reactant [R] decreases linearly with time. This indicates that the rate of reaction is constant and independent of reactant concentration. This is characteristic of a **zero-order reaction** (Rate = k). * **Curve 2 and 3**: The concentration of reactant [R] decreases non-linearly with time, and the rate of decrease slows down as co

Q: What are the options for this JEE Main Chemistry question?

A. The order of all the three reactions is same. · B. The rate constant of reaction 3 is larger than the rate constant of reaction 2 if the order of reaction is same for both. · C. The SI unit of rate constant of reaction 1 is s⁻¹. · D. Thermal decomposition of HI on gold surface is an example of reaction 2.

Question

Q.63. Consider the given graph showing variation of reactant concentration with time. Three different reactions were started with identical initial concentration of reactants. Which of the following statement is correct? [Figure: A graph showing reactant concentration [R] (mol L⁻¹) vs. time (t/s). There are three curves labeled 1, 2, and 3. Curve 1 is a straight line with a negative slope, indicating a constant rate. Curve 2 and 3 are non-linear, showing decreasing rates over time, with curve 3 decreasing faster than curve 2.]

FirstInTest · Accepted Answer

Let's analyze the curves:

*   **Curve 1**: The concentration of reactant [R] decreases linearly with time. This indicates that the rate of reaction is constant and independent of reactant concentration. This is characteristic of a **zero-order reaction** (Rate = k).
*   **Curve 2 and 3**: The concentration of reactant [R] decreases non-linearly with time, and the rate of decrease slows down as concentration decreases. This is characteristic of **first-order or higher-order reactions** (Rate = k[R]ⁿ, where n ≥ 1).

Now let's evaluate the statements:

(1) **The order of all the three reactions is same.** (Incorrect) Curve 1 is zero-order, while curves 2 and 3 are likely first or higher order.

(2) **The rate constant of reaction 3 is larger than the rate constant of reaction 2 if the order of reaction is same for both.** (Correct) For reactions of the same order, a faster decrease in concentration (steeper curve) indicates a larger rate constant. Curve 3 shows a faster decrease in [R] compared to curve 2, implying k₃ > k₂.

(3) **The SI unit of rate constant of reaction 1 is s⁻¹.** (Incorrect) Reaction 1 is zero-order. For a zero-order reaction, Rate = k. The unit of rate is mol L⁻¹ s⁻¹. Therefore, the unit of k for a zero-order reaction is mol L⁻¹ s⁻¹.

(4) **Thermal decomposition of HI on gold surface is an example of reaction 2.** (Incorrect) Thermal decomposition of HI on a gold surface is a zero-order reaction because the rate is limited by the surface area of the catalyst, not the concentration of HI. Thus, it would be an example of reaction 1, not reaction 2.

Answer

The order of all the three reactions is same.

Answer

The rate constant of reaction 3 is larger than the rate constant of reaction 2 if the order of reaction is same for both.

Answer

The SI unit of rate constant of reaction 1 is s⁻¹.

Answer

Thermal decomposition of HI on gold surface is an example of reaction 2.

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