If for a gas, `(R)/(C_V)=0.67`, the gas is

Options

A. diatomic
B. mixture of diatomic and polyatomic molecules
C. monoatomic
D. polyatomic

Answer

To solve the problem, we need to determine the type of gas based on the given ratio \( \frac{R}{C_V} = 0.67 \).

### Step-by-Step Solution:

1. **Understanding the relationship**: We know that the relationship between the gas constant \( R \), specific heat at constant volume \( C_V \), and the adiabatic index (or heat capacity ratio) \( \gamma \) is given by:
\[ \frac{R}{C_V} = \gamma - 1 \]

2. **Substituting the given value**: We substitute the given value into the equation:
\[ \frac{R}{C_V} = 0.67 \]

3. **Setting up the equation**: From the relationship, we can set up the equation:
\[ \gamma - 1 = 0.67 \]

4. **Solving for \( \gamma \)**: To find \( \gamma \), we add 1 to both sides:
\[ \gamma = 0.67 + 1 \]
\[ \gamma = 1.67 \]

5. **Identifying the type of gas**: The value of \( \gamma \) helps us identify the type of gas. For monoatomic gases, \( \gamma \) is typically around 1.67. Therefore, since we have found \( \gamma = 1.67 \), we conclude that the gas is a monoatomic gas.

### Final Answer:
The gas is a **monoatomic gas**.