The name given to an aqueous solution of HBr is:
A) hydrobromic acid.
B) hypobromous acid.
C) bromous acid.
D) bromic acid.
E) hydrogen bromide.
The correct answer and explanation is :
The correct answer is:
A) hydrobromic acid.
Explanation:
When hydrogen halides (HX, where X is a halogen) are dissolved in water, they form acids. The naming convention for acids depends on whether the acid is binary (contains only hydrogen and one other nonmetal) or oxyacid (contains hydrogen, oxygen, and another element).
1. Understanding the Nature of HBr
- Hydrogen bromide (HBr) is a binary compound composed of hydrogen (H) and bromine (Br).
- When HBr is dissolved in water, it dissociates completely, releasing H⁺ ions and forming an acidic solution.
- The aqueous solution of HBr is named hydrobromic acid according to IUPAC naming rules.
2. Naming Binary Acids
Binary acids consist of hydrogen and a nonmetal. The naming pattern follows:
- “Hydro-“ + root name of the nonmetal + “-ic acid”
- Example: HCl (hydrochloric acid), HI (hydroiodic acid), HBr (hydrobromic acid).
3. Why Other Choices Are Incorrect
- B) Hypobromous acid: Incorrect. This refers to HBrO, which is an oxyacid containing oxygen.
- C) Bromous acid: Incorrect. This refers to HBrO₂, another oxyacid.
- D) Bromic acid: Incorrect. This refers to HBrO₃, an oxyacid with three oxygen atoms.
- E) Hydrogen bromide: Incorrect. While “hydrogen bromide” is the correct name for the gaseous form (HBr in gas state), the question specifically asks about the aqueous solution, which is called hydrobromic acid.
Conclusion
The correct name for an aqueous solution of HBr is hydrobromic acid because it follows the naming rules for binary acids.