Rate of reaction curve for equilibrium can be like: [`r_(f)` = forward rate, `r_(b)` = backward rate]

Options

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Explanation

To solve the question regarding the rate of reaction curve for equilibrium, we can follow these steps:

### Step 1: Understand the Concept of Equilibrium
In a chemical reaction at equilibrium, the rate of the forward reaction (`r_f`) is equal to the rate of the backward reaction (`r_b`). This means that the concentration of reactants and products remains constant over time.

### Step 2: Analyze the Rate of Forward and Backward Reactions
As the reaction proceeds, initially, the forward reaction rate is high because there are more reactants available. As the reactants are converted into products, the concentration of reactants decreases, which in turn decreases the rate of the forward reaction. Conversely, the rate of the backward reaction starts low and increases as the concentration of products builds up.

### Step 3: Graphical Representation
On a graph where the x-axis represents time and the y-axis represents the rate of reaction:
- The curve for the forward reaction (`r_f`) starts high and decreases over time.
- The curve for the backward reaction (`r_b`) starts low and increases over time.
- At equilibrium, these two curves will intersect, indicating that `r_f = r_b`.

### Step 4: Identify the Equilibrium Point
The point where the two curves intersect represents the equilibrium state. At this point, the rates of the forward and backward reactions are equal, and the concentrations of reactants and products remain constant.

### Step 5: Conclusion
The correct representation of the rate of reaction curve for equilibrium shows that the forward and backward rates will eventually become equal, leading to a stable state where no net change occurs in the concentrations of reactants and products.

### Summary of the Solution
1. Understand that at equilibrium, `r_f = r_b`.
2. Recognize that the forward reaction rate decreases while the backward reaction rate increases until they are equal.
3. Graph the rates over time to visualize the intersection point, which indicates equilibrium.