Which of the following hydrocarbons does not decolourise bromine water?

Options

A. `C_(10)H_(22)`
B. `C_(6)H_(12)`
C. `C_(10)H_(18)`
D. `C_(10)H_(20)`

Explanation

To determine which hydrocarbon does not decolorize bromine water, we need to understand the concept of saturation in hydrocarbons.

### Step-by-Step Solution:

1. **Understand the Test**: The bromine water test is used to detect unsaturation in organic compounds. Unsaturation refers to the presence of double or triple bonds in hydrocarbons.

2. **Identify Hydrocarbon Types**:
- **Alkenes**: These are unsaturated hydrocarbons with at least one double bond. Their general formula is \( C_nH_{2n} \). They will decolorize bromine water.
- **Alkynes**: These are also unsaturated hydrocarbons with at least one triple bond. Their general formula is \( C_nH_{2n-2} \). They will also decolorize bromine water.
- **Alkanes**: These are saturated hydrocarbons with only single bonds. Their general formula is \( C_nH_{2n+2} \). They do not decolorize bromine water.

3. **Analyze Given Hydrocarbons**:
- Let's say we have the following hydrocarbons:
- \( C_6H_{12} \)
- \( C_{10}H_{18} \)
- \( C_{10}H_{22} \)
- \( C_{8}H_{16} \)

- Now, we will classify them based on their formulas:
- For \( C_6H_{12} \): This follows the formula \( C_nH_{2n} \) (alkene).
- For \( C_{10}H_{18} \): This follows the formula \( C_nH_{2n-2} \) (alkyne).
- For \( C_{10}H_{22} \): This follows the formula \( C_nH_{2n+2} \) (alkane).
- For \( C_{8}H_{16} \): This follows the formula \( C_nH_{2n} \) (alkene).

4. **Conclusion**: The hydrocarbon that does not decolorize bromine water is \( C_{10}H_{22} \) because it is an alkane (saturated) and does not have any double or triple bonds.

### Final Answer:
**The hydrocarbon that does not decolorize bromine water is \( C_{10}H_{22} \).**