The number average molecular mass and mass average molecular mass of a polymer are respectively 30,000 and 40,000. The poly dispersity of the polymer is:

Options

A. `lt 1`
B. `lt 1`
C. 1
D. 0

Answer

To find the polydispersity index (PDI) of a polymer, we use the formula:

\[ \text{Polydispersity Index (PDI)} = \frac{\text{Mass Average Molecular Mass (M}_w\text{)}}{\text{Number Average Molecular Mass (M}_n\text{)}} \]

Given:
- Mass Average Molecular Mass (M_w) = 40,000
- Number Average Molecular Mass (M_n) = 30,000

Now, we can substitute the values into the formula:

\[ \text{PDI} = \frac{M_w}{M_n} = \frac{40,000}{30,000} \]

Next, we can simplify this fraction:

\[ \text{PDI} = \frac{40}{30} = \frac{4}{3} \approx 1.33 \]

Thus, the polydispersity index of the polymer is approximately 1.33.

### Final Answer:
The polydispersity of the polymer is approximately 1.33.