In the electrothermal process, the compound displaced by silica from calcium phosphate is

Options

A. Calcium
B. Phosphine
C. Phosphorus
D. phosphorus pentoxide

Explanation

To solve the question regarding the electrothermal process and the compound displaced by silica from calcium phosphate, we can follow these steps:

### Step 1: Understand the Electrothermal Process
The electrothermal process is a method used to extract certain metals from their ores. In this process, high temperatures are achieved using electrical energy, which can facilitate chemical reactions that would not occur at lower temperatures.

**Hint:** Research the electrothermal process to understand its applications and reactions involved.

### Step 2: Identify Calcium Phosphate
Calcium phosphate is a chemical compound with the formula Ca3(PO4)2. It is commonly found in nature and is used in various applications, including fertilizers and as a food additive.

**Hint:** Look up the structure and properties of calcium phosphate to understand its reactivity.

### Step 3: Analyze the Reaction with Silica
In the electrothermal process, silica (SiO2) can react with calcium phosphate. The reaction typically involves the formation of calcium silicate and the release of phosphorous compounds.

**Hint:** Consider the chemical reactions that involve silica and calcium phosphate to identify the products formed.

### Step 4: Write the Reaction Equation
The general reaction can be represented as:
\[ \text{Ca}_3(\text{PO}_4)_2 + \text{SiO}_2 \rightarrow \text{CaSiO}_3 + \text{P}_2\text{O}_5 \]
In this reaction, calcium silicate (CaSiO3) is formed, and phosphorous pentoxide (P2O5) is released.

**Hint:** Balancing the chemical equation can help clarify the compounds involved in the reaction.

### Step 5: Identify the Displaced Compound
From the reaction, we can see that silica displaces phosphorous pentoxide from calcium phosphate. Therefore, the compound displaced by silica from calcium phosphate is phosphorous pentoxide (P2O5).

**Hint:** Focus on the products of the reaction to determine which compound is displaced.

### Final Answer
The compound displaced by silica from calcium phosphate in the electrothermal process is phosphorous pentoxide (P2O5).