According to Graham’s law, the rate of diffusion of `CO, O_2, N_2` and `CO_2` follows the order

Options

A. `CO = N_2 gt O_2 gt CO_2`
B. `CO = N_2 gt CO_2 gt O_2`
C. `O_2 gt CO = N_2 gt CO_2`
D. `CO_2 gt O_2 gt CO = N_2`

Explanation

To solve the problem regarding the order of diffusion rates of CO, O2, N2, and CO2 according to Graham's law, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Graham's Law**: Graham's law states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. This can be expressed mathematically as:
\[ \text{Rate} \propto \frac{1}{\sqrt{M}} \]
where \( M \) is the molar mass of the gas.

2. **Determine the Molar Masses**:
- CO (Carbon monoxide):
\[ \text{Molar mass of CO} = 12 \, (\text{C}) + 16 \, (\text{O}) = 28 \, \text{g/mol} \]
- O2 (Oxygen):
\[ \text{Molar mass of O2} = 16 \, (\text{O}) + 16 \, (\text{O}) = 32 \, \text{g/mol} \]
- N2 (Nitrogen):
\[ \text{Molar mass of N2} = 14 \, (\text{N}) + 14 \, (\text{N}) = 28 \, \text{g/mol} \]
- CO2 (Carbon dioxide):
\[ \text{Molar mass of CO2} = 12 \, (\text{C}) + 16 \, (\text{O}) + 16 \, (\text{O}) = 44 \, \text{g/mol} \]

3. **List the Molar Masses**:
- CO: 28 g/mol
- N2: 28 g/mol
- O2: 32 g/mol
- CO2: 44 g/mol

4. **Rank the Molar Masses**:
- The order of increasing molar mass is:
- CO = N2 < O2 < CO2
- This means CO and N2 have the same molar mass, which is lower than O2, and CO2 has the highest molar mass.

5. **Determine the Order of Diffusion Rates**:
- Since the rate of diffusion is inversely proportional to the square root of the molar mass, the gas with the lowest molar mass will diffuse the fastest.
- Therefore, the order of diffusion rates from fastest to slowest is:
- CO = N2 > O2 > CO2

### Final Answer:
The order of diffusion according to Graham's law is:
**CO = N2 > O2 > CO2**