The oxidation number of hydrogen (H) in hydrogen fluoride (HF) is +1.
Understanding Oxidation Numbers
Oxidation numbers, also known as oxidation states, are essential tools in chemistry for tracking electron distribution in compounds and during chemical reactions. They represent the hypothetical charge an atom would have if all bonds were ionic. Assigning these numbers follows a set of established rules, which help determine how elements share or gain electrons when forming molecules.
Determining H Oxidation in HF
To determine the oxidation number of hydrogen in hydrogen fluoride (HF), we apply the standard rules for assigning oxidation states:
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Fluorine's Oxidation State: Fluorine (F) is the most electronegative element on the periodic table. As a rule, fluorine always has an oxidation number of -1 in all its compounds. This is a primary rule due to its strong electron-attracting capability.
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Neutral Compound Rule: For a neutral compound like HF, the sum of the oxidation numbers of all atoms must equal zero.
Given these rules, we can set up a simple equation:
(Oxidation number of H) + (Oxidation number of F) = 0
Let 'x' be the oxidation number of hydrogen:
x + (-1) = 0
To solve for x:
x = +1
Therefore, the oxidation number of hydrogen in HF is +1. This value is consistent with the established chemical principles regarding hydrogen's behavior when bonded to a more electronegative nonmetal. Hydrogen typically exhibits a +1 oxidation state when combined with nonmetals, and a -1 oxidation state when combined with metals (e.g., in metal hydrides like NaH).
Summary of Oxidation States in HF
The oxidation states within the hydrogen fluoride molecule can be clearly summarized:
| Element | Oxidation Number | Rationale |
|---|---|---|
| Hydrogen (H) | +1 | Calculated based on the sum of oxidation numbers equaling zero in a neutral compound, and fluorine's fixed oxidation state. |
| Fluorine (F) | -1 | Fluorine is the most electronegative element and always takes a -1 oxidation state in compounds. |
| Total (HF) | 0 | The sum of oxidation numbers in a neutral molecule must be zero. |
Understanding how to assign oxidation numbers is fundamental for studying redox reactions, balancing chemical equations, and predicting chemical behavior.
