A chemical reaction involves two reacting species. The rate of reaction is directly proportional to the conc. Of one of them and inversely proportional to the concentration of the other. The order of reaction is

Options

A. 1
B. 2
C. zero
D. unpredictable

Explanation

To determine the order of the reaction based on the given information, we can follow these steps:

### Step 1: Understand the relationship between rate and concentration
The problem states that the rate of reaction is directly proportional to the concentration of one reactant (let's call it A) and inversely proportional to the concentration of the other reactant (let's call it B). This can be expressed mathematically as:
\[ \text{Rate} \propto \frac{[A]}{[B]} \]

### Step 2: Write the rate law expression
From the proportionality, we can write the rate law expression as:
\[ \text{Rate} = k \cdot [A]^1 \cdot [B]^{-1} \]
where \( k \) is the rate constant.

### Step 3: Identify the order of reaction
In the rate law expression, the exponent of \( [A] \) is 1 (since it is directly proportional), and the exponent of \( [B] \) is -1 (since it is inversely proportional).

The overall order of the reaction is calculated by summing the individual orders:
\[ \text{Order} = 1 + (-1) = 0 \]

### Step 4: Conclusion
Thus, the order of the reaction is zero.

### Final Answer
The order of the reaction is **0** (zero order reaction).

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