Question

In the reaction, P\(_2\)O\(_5\) + 3CaO \(\rightarrow\) Ca\(_3\)(PO\(_4\))\(_2\), P\(_2\)O\(_5\) acts as

• A. acidic flux
• B. basic flux
• C. basic impurity
• D. acidic impurity

Hint:

Acidic flux removes basic impurities; basic flux removes acidic impurities.

Answer 1

The Correct Option is A

To solve this question, we need to understand the role of \(P_2O_5\) in the given chemical reaction:

\(P_2O_5 + 3CaO \rightarrow Ca_3(PO_4)_2\)

• Fluxes in metallurgy: A flux is a chemical cleaning agent used primarily in metal joining processes. It can be classified into two categories based on its chemical nature:
  • Acidic flux: A flux that reacts with basic impurities to form slag.
  • Basic flux: A flux that reacts with acidic impurities to form slag.
• Identifying the nature of \(P_2O_5\): Phosphorus pentoxide, \(P_2O_5\), is known to be an acidic oxide. In chemical reactions, it behaves like an acid because it can react with basic oxides.
• Role of \(P_2O_5\) in the reaction: In the provided reaction, \(P_2O_5\) is reacting with calcium oxide, \(CaO\), which is basic in nature, to form calcium phosphate, \(Ca_3(PO_4)_2\). This shows that \(P_2O_5\) is acting as an acidic flux by combining with the basic oxide to produce a compound. Thus, it helps in creating a homogeneous mixture free of basic impurities.

Based on this analysis, \(P_2O_5\) acts as an acidic flux.

Therefore, the correct answer is:

acidic flux