Bauxide ore is made up of `Al_(2)O_(3) + SiO_(2) + TiO_(2) + Fe_(2) O_(3)`. This ore is treated with conc. `NaOH` solution at `500 K` and `35` bar pressure for a few hours and filtered hot. In the filtrate, the species present are

Options

A. `NaAl(OH)_(4)` only
B. `Na_(2)Ti(OH)_(6)` only
C. `NaAl(OH)_(4)` and `Na_(2)SiO_(3)` both
D. `Na_(2)SiO_(3)` only

Explanation

To solve the problem, we need to analyze the components of bauxite ore and their reactions with concentrated sodium hydroxide (NaOH) under the specified conditions.

### Step-by-Step Solution:

1. **Identify the Components of Bauxite Ore**:
Bauxite ore primarily consists of:
- Aluminum oxide (Al₂O₃)
- Silicon dioxide (SiO₂)
- Titanium dioxide (TiO₂)
- Iron(III) oxide (Fe₂O₃)

2. **Understand the Reaction Conditions**:
The ore is treated with concentrated NaOH at a temperature of 500 K and a pressure of 35 bar. Under these conditions, the reactivity of the components will vary.

3. **Determine the Reactivity of Each Component**:
- **Aluminum oxide (Al₂O₃)**: This is an amphoteric oxide, which means it can react with both acids and bases. It will react with NaOH to form sodium aluminate.
- **Silicon dioxide (SiO₂)**: This is an acidic oxide and will also react with NaOH to form sodium silicate.
- **Titanium dioxide (TiO₂)**: This is a basic oxide and does not react with NaOH.
- **Iron(III) oxide (Fe₂O₃)**: This is also a basic oxide and does not react with NaOH.

4. **Write the Reaction for Aluminum Oxide**:
The reaction of aluminum oxide with sodium hydroxide can be represented as:
\[ \text{Al}_2\text{O}_3 + 2 \text{NaOH} + 3 \text{H}_2\text{O} \rightarrow 2 \text{NaAl(OH)}_4 \]
This product, sodium aluminate, is soluble in water.

5. **Write the Reaction for Silicon Dioxide**:
The reaction of silicon dioxide with sodium hydroxide can be represented as:
\[ \text{SiO}_2 + 2 \text{NaOH} \rightarrow \text{Na}_2\text{SiO}_3 + \text{H}_2\text{O} \]
This product, sodium silicate, is also soluble in water.

6. **Filtration of the Mixture**:
After the reactions, the mixture is filtered hot. The insoluble residues will be TiO₂ and Fe₂O₃, while the soluble products (sodium aluminate and sodium silicate) will remain in the filtrate.

7. **Conclusion**:
Therefore, the species present in the filtrate after filtering the treated bauxite ore will be sodium aluminate (NaAl(OH)₄) and sodium silicate (Na₂SiO₃).

### Final Answer:
The species present in the filtrate are sodium aluminate (NaAl(OH)₄) and sodium silicate (Na₂SiO₃).

---