The chemical used for cooling in refrigeration is

Options

A. `CO_(2)`
B. `NH_(4)OH`
C. `NH_(4)Cl`
D. Liquid `NH_(3)`

Explanation

To determine the chemical used for cooling in refrigeration, we can follow these steps:

### Step 1: Identify Common Refrigerants
Refrigerants are substances used in refrigeration systems to absorb heat from the environment. Common refrigerants include:
- Chlorofluorocarbons (CFCs)
- Hydrocarbons
- Ammonia (NH3)
- Sulfur dioxide (SO2)

### Step 2: Evaluate Each Option
1. **Chlorofluorocarbons (CFCs)**: These were widely used in the past but are now being phased out due to their harmful effects on the ozone layer.
2. **Hydrocarbons**: Non-halogenated hydrocarbons like propane and isobutane are used in some refrigeration systems but are less common in traditional systems.
3. **Ammonia (NH3)**: This is a very efficient refrigerant and is commonly used in industrial refrigeration systems.
4. **Sulfur Dioxide (SO2)**: This was used in early refrigeration systems but is less common now due to its toxicity.

### Step 3: Conclusion
Based on the evaluation, the most commonly used chemical for cooling in refrigeration today is **Ammonia (NH3)**, especially in industrial applications.

### Final Answer
The chemical used for cooling in refrigeration is **Liquid Ammonia (NH3)**.

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