Density of which of the following substance not decreases on adding in `Br_(2)` vapours :

Options

A. `C CI_(4)`
B. `CS_(2)`
C. Ether
D. Coke

Answer

To determine which substance's density does not decrease upon adding Br₂ vapors, we need to analyze the behavior of each substance in the presence of bromine.

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify a substance whose density remains unchanged when Br₂ vapors are added.

2. **Identify the Substances**: The question mentions several substances, including coke. We will focus on coke and its interaction with Br₂ vapors.

3. **Analyze Coke**:
- Coke is primarily composed of carbon in its elemental form.
- The structure of coke does not allow for a reaction with bromine, as carbon does not satisfy its valencies with bromine.

4. **Consider the Reaction**:
- Since there is no reaction between elemental carbon (in coke) and bromine, there will be no change in the mass or volume of coke when Br₂ vapors are introduced.
- Therefore, the density of coke remains constant.

5. **Conclusion**: Since the density of coke does not change upon the addition of Br₂ vapors, it is the correct answer to the question.

### Final Answer:
The density of coke does not decrease on adding Br₂ vapors.