Which is not a binary acid?
A. hydrochloric acid
B. hydrobromic acid
C. hydroiodic acid
D. none of the above
The correct answer and explanation is :
The correct answer is D. none of the above.
Here’s why:
Binary acids are acids that consist of only two elements: hydrogen and one other nonmetal. The formula of binary acids is generally written as HX, where X represents a halogen or another nonmetal. The key characteristic of binary acids is that they contain just two types of elements: hydrogen and a single other element.
Let’s go over each of the given options:
- Hydrochloric acid (HCl): This is a binary acid because it consists of hydrogen (H) and chlorine (Cl), which is a nonmetal. It follows the general formula for binary acids: HX.
- Hydrobromic acid (HBr): This is also a binary acid because it consists of hydrogen (H) and bromine (Br), which is another halogen and a nonmetal. This also fits the formula HX.
- Hydroiodic acid (HI): This is another binary acid, containing hydrogen (H) and iodine (I), another halogen. It follows the HX structure as well.
- None of the above: Since all three acids (hydrochloric acid, hydrobromic acid, and hydroiodic acid) are binary acids, the correct answer is D. none of the above because none of them can be classified as non-binary acids.
Explanation:
The defining feature of binary acids is their structure, which must consist of only two elements—hydrogen and a nonmetal. The acids listed (hydrochloric acid, hydrobromic acid, and hydroiodic acid) all conform to this definition, as they are composed of hydrogen and a halogen, which is a nonmetal. These acids are all examples of hydrogen halides in aqueous solution, which are strong acids when dissolved in water.
On the other hand, non-binary acids would include compounds that contain more than two elements. A common example of a non-binary acid is sulfuric acid (H₂SO₄), which contains hydrogen, sulfur, and oxygen.