Question

Predict the chemical formula for each of the following ternary oxyacids given the formula of hypochlorous acid, \(\mathrm{HClO}(a q)\) (a) hypoiodous acid (b) hypobromous acid

Short answer

Hypoiodous acid: \(\mathrm{HIO}(aq)\); Hypobromous acid: \(\mathrm{HBrO}(aq)\).

Step-by-step solution

Understand the given information

We are given the chemical formula for hypochlorous acid, which is \(\mathrm{HClO}\ (aq)\). This is an example of a ternary oxyacid, which typically contains hydrogen, an element (in this case, chlorine), and oxygen.

Identify the pattern

The formula \(\mathrm{HClO}\) shows that the formula for a hypohalous acid contains one hydrogen, one halogen, and one oxygen. This pattern will be applied to find the formulas for the other hypohalous acids.

Apply the pattern to hypoiodous acid

For hypoiodous acid, replace chlorine (\(\mathrm{Cl}\)) with iodine (\(\mathrm{I}\)) in the hypochlorous acid formula. This gives the formula \(\mathrm{HIO}\ (aq)\).

Apply the pattern to hypobromous acid

For hypobromous acid, replace chlorine (\(\mathrm{Cl}\)) with bromine (\(\mathrm{Br}\)) in the hypochlorous acid formula. This results in the formula \(\mathrm{HBrO}\ (aq)\).

Key concepts

Hypochlorous Acid

Hypochlorous acid is a type of ternary oxyacid. The term "ternary" indicates that the compound consists of three different elements: hydrogen, a halogen, and oxygen. In this particular case of hypochlorous acid, the chemical formula is \( \text{HClO} \). Here, the "hypo-" prefix is indicative of the compound having the lowest number of oxygen atoms among the oxyacids of the same halogen series. Hypochlorous acid is known for being a weak acid, meaning that it doesn’t completely dissociate in water. This uniqueness significantly impacts its reactivity and use in disinfection as it is gentle yet effective in sanitizing surfaces and water. It's important to note that although hypochlorous acid is related to chlorine bleach, they are not the same, further exemplifying the subtle but important differences indicated by chemical formulas.

Chemical Formulas

Chemical formulas are vital tools in chemistry because they provide information about the specific elements present in a compound and their ratios. For instance, in the chemical formula \( \text{HClO} \), it is clear that there is one hydrogen atom, one chlorine atom, and one oxygen atom. This clarifies the composition of hypochlorous acid. Additionally, the suffix and prefixes in the name (like "hypo" and "ous") provide indicators of the oxygen levels. Formulas aren’t just random letters and numbers; they are shorthand for detailed instructions on chemical behaviors and properties. Knowing how to read and write these formulas allows chemists to predict reactions and interactions between compounds. Furthermore, formulas provide a basis for understanding the formation of various compounds in a particular halogen group and beyond.

Halogen Replacement

Halogen replacement is a simple yet essential concept in chemistry, particularly when dealing with ternary oxyacids. The process involves substituting one halogen with another to form a new compound. For example, hypochlorous acid \( \text{HClO} \) becomes hypoiodous acid \( \text{HIO} \) when iodine replaces chlorine. Similarly, bromine replaces chlorine in hypochlorous acid to form hypobromous acid \( \text{HBrO} \). This method of replacement highlights the importance of patterns and periodic trends within the halogen group, where similar properties allow for easy substitution. Understanding halogen replacement not only adds new members to the oxyacid family but also enables chemists to predict the stability and reactivity of the new compounds they create. It showcases the consistency within the periodic table and emphasizes the relations between elements that chemists creatively exploit to synthesize desired outcomes.