State the ionic charge for each of the following substances: (a) chlorine gas molecules (b) chloride ions (c) hypochlorite ion (d) chlorine compounds
The Correct Answer and Explanation is:
Let’s break this down and discuss each part:
(a) Chlorine gas molecules (Cl₂)
Chlorine gas is made up of chlorine atoms covalently bonded to each other. Since it’s a molecule, chlorine gas (Cl₂) does not carry an ionic charge. The chlorine atoms share electrons equally in the covalent bond, so Cl₂ molecules are neutral.
(b) Chloride ions (Cl⁻)
When chlorine gains an electron to complete its octet (full outer electron shell), it becomes a negatively charged ion. The extra electron gives chlorine a charge of -1. So, chloride ions (Cl⁻) have an ionic charge of -1.
(c) Hypochlorite ion (ClO⁻)
The hypochlorite ion is a polyatomic ion composed of one chlorine atom bonded to one oxygen atom. The chlorine atom in the hypochlorite ion has a -1 charge. Therefore, hypochlorite ions (ClO⁻) also carry a -1 charge.
(d) Chlorine compounds
Chlorine forms a variety of compounds, and the ionic charge depends on the specific compound in question. For example:
- Chlorine in sodium chloride (NaCl): In sodium chloride, chlorine gains one electron from sodium, becoming a chloride ion (Cl⁻), which has a -1 charge.
- Chlorine in chlorine dioxide (ClO₂): In this compound, chlorine typically has a positive oxidation state, specifically +4, as the oxygen atoms are highly electronegative.
- Chlorine in chlorine trifluoride (ClF₃): Chlorine has a +3 oxidation state in this compound, as it bonds with fluorine, a highly electronegative element.
Conclusion
- Cl₂: Neutral (no charge).
- Cl⁻: -1 charge.
- ClO⁻: -1 charge.
- Chlorine compounds: The charge of chlorine can vary based on the compound, from -1 in ionic compounds like NaCl to +3 or +4 in others.
