Which of the following plot of pressure (P) Vs time satisfy decomposition of Kl on gold surafce.

Options

A.
B.
C.
D.

Explanation

To solve the question regarding the decomposition of HI on the surface of gold, we need to analyze the behavior of the pressure of HI over time, considering that this reaction follows zero-order kinetics. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Reaction
The decomposition of hydrogen iodide (HI) on the gold surface can be represented as:
\[ 2 HI \rightarrow H_2 + I_2 \]
In this reaction, HI decomposes into hydrogen gas (H2) and iodine gas (I2).

**Hint:** Remember that in a zero-order reaction, the rate of reaction is constant and does not depend on the concentration of the reactant.

### Step 2: Identify the Kinetics
Since the decomposition of HI on the gold surface follows zero-order kinetics, the rate of reaction can be expressed as:
\[ \text{Rate} = k \]
where \( k \) is the rate constant.

**Hint:** Zero-order kinetics implies that the concentration of the reactant does not affect the rate of the reaction.

### Step 3: Relate Pressure to Concentration
For gases, pressure is directly proportional to concentration. Thus, if the concentration of HI decreases over time, the pressure of HI will also decrease. The relationship can be expressed as:
\[ P_{HI} = P_0 - kt \]
where \( P_0 \) is the initial pressure of HI, \( k \) is the rate constant, and \( t \) is time.

**Hint:** As the reaction progresses, the pressure of HI will decrease linearly over time due to the constant rate of reaction.

### Step 4: Analyze the Options
Now, let’s analyze the provided options:
- **Option A:** HI's concentration remains constant. (Not possible in decomposition)
- **Option B:** Concentration of HI decreases and H2 concentration increases. (Correct)
- **Option C:** HI concentration decreases and H2 concentration remains constant. (Not correct)
- **Option D:** All concentrations remain constant. (Impossible)

**Hint:** Look for the option that shows a decrease in reactant pressure and an increase in product pressure.

### Step 5: Conclusion
Based on the analysis, the correct plot of pressure vs. time that satisfies the decomposition of HI on the gold surface is **Option B**, where the pressure of HI decreases over time while the pressure of H2 increases.

**Final Answer:** Option B is the correct answer.