During roasting & calcination emitted gases procduce which of the following effect

Options

A. Photochecmical smog, acid rain
B. acid rain, global warming
C. photochemical smog, global warming
D. acid rain, ozone depetion

Answer

To solve the question regarding the effects of gases emitted during roasting and calcination, we will analyze the processes involved and the resulting gases.

### Step-by-Step Solution:

1. **Understanding Calcination**:
- Calcination is the process where an ore is heated in the absence of air or in a limited supply of oxygen.
- This process typically converts carbonates into oxides while releasing carbon dioxide (CO2) gas.
- **Example**: When calcium carbonate (CaCO3) is heated, it decomposes to form calcium oxide (CaO) and carbon dioxide (CO2):
\[ \text{CaCO}_3 \, (s) \rightarrow \text{CaO} \, (s) + \text{CO}_2 \, (g) \]

2. **Understanding Roasting**:
- Roasting involves heating an ore in the presence of oxygen.
- This process converts sulfides into oxides while releasing sulfur dioxide (SO2) gas.
- **Example**: When zinc sulfide (ZnS) is roasted, it reacts with oxygen to form zinc oxide (ZnO) and sulfur dioxide (SO2):
\[ \text{2 ZnS} \, (s) + \text{3 O}_2 \, (g) \rightarrow \text{2 ZnO} \, (s) + \text{2 SO}_2 \, (g) \]

3. **Identifying the Effects of Emitted Gases**:
- The gases emitted during these processes have specific environmental effects:
- **CO2**: This gas is a greenhouse gas that contributes to global warming by trapping heat in the atmosphere.
- **SO2**: This gas can react with water vapor in the atmosphere to form sulfuric acid (H2SO4), which is a major contributor to acid rain.

4. **Analyzing the Options**:
- **Option 1**: Photochemical smog, smoke, and acid rain - Not all components are relevant.
- **Option 2**: Acid rain and global warming - This option is valid as both effects are produced by the gases emitted.
- **Option 3**: Photochemical smog, smoke, and global warming - Not all components are relevant.
- **Option 4**: Acid rain and ozone depletion - Ozone depletion is not directly related to the gases emitted during roasting and calcination.

5. **Conclusion**:
- The correct answer is **Option 2: Acid rain and global warming**, as both are direct effects of the gases emitted during roasting and calcination.