Which is a non oxy-acid?
A sulfuric acid
B. nitric acid
C. hydrofluoric acid
D. phosphoric acid
The correct answer and explanation is :
The correct answer is: C. Hydrofluoric acid
Explanation:
Acids are broadly classified into two main categories based on their composition:
- Oxy-acids (or oxoacids): These contain hydrogen, oxygen, and another element (usually a non-metal). Examples include:
- Sulfuric acid (H₂SO₄): contains sulfur, hydrogen, and oxygen.
- Nitric acid (HNO₃): contains nitrogen, hydrogen, and oxygen.
- Phosphoric acid (H₃PO₄): contains phosphorus, hydrogen, and oxygen.
- Non-oxy acids (also called hydro acids): These are binary acids composed of hydrogen and one other non-metal element, but they do not contain oxygen. An example is:
- Hydrofluoric acid (HF): composed only of hydrogen and fluorine.
Since hydrofluoric acid (HF) contains only hydrogen and fluorine and no oxygen, it is classified as a non-oxy acid. This distinguishes it clearly from the other options provided, which all contain oxygen atoms and are therefore oxy-acids.
Understanding the nature of acids is essential in both chemistry and its applications. Oxy-acids typically arise from the combination of water with non-metal oxides (like SO₃ or NO₂), forming acids with distinct polyatomic anions such as sulfate (SO₄²⁻) and nitrate (NO₃⁻). These acids often have multiple ionizable hydrogens and are strong electrolytes.
In contrast, hydrofluoric acid, despite being a weak acid in aqueous solution, is extremely dangerous due to its ability to penetrate tissues and bind calcium and magnesium in the body. Its non-oxy nature makes its chemical behavior quite different from sulfuric, nitric, or phosphoric acids.
In summary, HF is a non-oxy acid, while the other options are all oxy-acids because they contain oxygen as part of their structure.