The reaction `2H_2O_2 to 2H_2O + O_2` is a

Options

A. Zero order reaction
B. First order reaction
C. Second order reaction
D. Third order reaction

Answer

To determine the order of the reaction \(2H_2O_2 \rightarrow 2H_2O + O_2\), we can follow these steps:

### Step 1: Identify the Reaction
The given reaction involves the decomposition of hydrogen peroxide (\(H_2O_2\)) into water (\(H_2O\)) and oxygen gas (\(O_2\)).

### Step 2: Understand Reaction Order
The order of a reaction is determined by the sum of the powers of the concentration terms in the rate law expression. It can be zero, first, second, or higher order based on how the rate of reaction depends on the concentration of the reactants.

### Step 3: Experimental Evidence
It is known from experimental studies that the decomposition of hydrogen peroxide is a first-order reaction. This means that the rate of reaction is directly proportional to the concentration of one of the reactants, in this case, \(H_2O_2\).

### Step 4: Rate Law Expression
For a first-order reaction, the rate law can be expressed as:
\[ \text{Rate} = k[H_2O_2]^1 \]
Here, \(k\) is the rate constant, and the exponent of the concentration of \(H_2O_2\) is 1, indicating that it is a first-order reaction.

### Step 5: Calculate the Order
Since the order of a reaction is the sum of the powers of the concentration terms in the rate law, and we have:
\[ \text{Order} = 1 \]
This confirms that the reaction is indeed a first-order reaction.

### Conclusion
Thus, the reaction \(2H_2O_2 \rightarrow 2H_2O + O_2\) is classified as a **first-order reaction**.

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