Victor Meyer's method for determination of molecular mass is applicable only to volatile organic compounds.

Explanation

### Step-by-Step Solution:

1. **Understanding Victor Meyer's Method**:
- Victor Meyer's method is a laboratory technique used to determine the molecular mass of volatile organic compounds. It is based on the principle of gas displacement.

2. **Process Overview**:
- A known mass of a volatile liquid or solid is heated in a diphtheria tube, which converts it into vapor. This vapor then displaces a certain volume of air.

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