How mant reaction can show slag formation process from the given reaction ?
(i) `SiO_(2) + CaO rarr CaSiO_(3)`
(ii) `FeO + SiO_(2) rarr FeSiO_(3)`
(iii) `CaO + P_(2)O_(5) rarr Ca_(3)(PO_(4))_(2)`
(iv) `Cr_(2)O_(3) + 2Al rarr Al_(2)O_(3) + 2Cr`
(v) `MgCO_(3) + SiO_(2) rarr MgSiO_(3) + CO_(2)`.

Options

A. (i) `SiO_(2) `- Acidic flux (ii) `MgO-` Basic flux
B. (i) `SiO_(2) `- Basic flux (ii) MgO - Acidic flux
C. (i) `SiO_(2) `- Basic flux (ii) MgO-Basic flux
D. (i) `SiO_(2)`-Acidic flux (ii) MgO -Acidic flux

Explanation

To determine how many reactions can show slag formation from the given reactions, we need to identify which reactions involve the combination of a flux and gangue to produce slag. A flux is typically a substance that helps to lower the melting point of the materials, while gangue is the unwanted material that is removed during the extraction of metals.

Let's analyze each reaction step by step:

1. **Reaction (i): `SiO2 + CaO → CaSiO3`**
- **Analysis**: Here, SiO2 acts as an acidic flux and CaO acts as a basic flux. The combination of these two will result in the formation of slag (CaSiO3).
- **Conclusion**: This reaction shows slag formation.

2. **Reaction (ii): `FeO + SiO2 → FeSiO3`**
- **Analysis**: In this case, SiO2 is again acting as an acidic flux, while FeO can be considered as gangue. The combination results in the formation of slag (FeSiO3).
- **Conclusion**: This reaction shows slag formation.

3. **Reaction (iii): `CaO + P2O5 → Ca3(PO4)2`**
- **Analysis**: Here, CaO is a basic flux and P2O5 can be considered as gangue. The product formed is not typically classified as slag in metallurgical processes.
- **Conclusion**: This reaction does not show slag formation.

4. **Reaction (iv): `Cr2O3 + 2Al → Al2O3 + 2Cr`**
- **Analysis**: In this reaction, there is no flux involved. The reaction is a reduction process and does not involve the formation of slag.
- **Conclusion**: This reaction does not show slag formation.

5. **Reaction (v): `MgCO3 + SiO2 → MgSiO3 + CO2`**
- **Analysis**: In this case, MgCO3 can act as a basic flux and SiO2 as an acidic flux. The combination results in the formation of slag (MgSiO3).
- **Conclusion**: This reaction shows slag formation.

Now, let's summarize the reactions that show slag formation:
- Reaction (i)
- Reaction (ii)
- Reaction (v)

**Total reactions showing slag formation**: 3

### Final Answer:
**3 reactions show slag formation.**