For a reaction `A + 2B rarr C`, rate is given by `R = K [A] [B]^(2)`. The order of reaction is:

Options

A. 3
B. 6
C. 5
D. 7

Explanation

To determine the order of the reaction given by the rate expression \( R = k [A] [B]^2 \), we will follow these steps:

### Step 1: Understand the Rate Expression
The rate expression for the reaction is given as:
\[ R = k [A] [B]^2 \]
Here, \( [A] \) and \( [B] \) represent the concentrations of reactants A and B, respectively.

### Step 2: Identify the Exponents
In the rate expression, the exponent of \( [A] \) is 1 (since it is not explicitly written, it is understood to be 1), and the exponent of \( [B] \) is 2.

### Step 3: Calculate the Order of the Reaction
The order of a reaction is defined as the sum of the powers of the concentration terms in the rate law. Therefore, we add the exponents:
\[ \text{Order} = \text{Exponent of } [A] + \text{Exponent of } [B] = 1 + 2 = 3 \]

### Step 4: Conclusion
Thus, the order of the reaction is 3.

### Final Answer
The order of the reaction is **3**.

---