Final answer:
The oxidation number for tin (Sn) in SnCl₃⁻ is +2, and each chlorine (Cl) atom has an oxidation number of -1, satisfying the overall -1 charge of the ion.
Step-by-step explanation:
To find the oxidation number of each type of atom in SnCl₃⁻, we can use a set of rules for assigning oxidation states. We know from the rules that in ionic compounds like SnCl3-, it's useful to consider the cation and anion separately. For halogens such as chlorine (Cl), we often assign a -1 oxidation number when they are not combined with oxygen or more electronegative elements. Since there are three chlorines, and assuming each chlorine has an oxidation number of -1, their combined oxidation number is -3.
As the ion carries an overall -1 charge, we balance the oxidation numbers of chlorine with that of tin (Sn) to equal the charge on the ion. Thus, if chlorine has an oxidation number of -3 for all three atoms together and the ion has a -1 charge, tin must have an oxidation number that makes the sum -1. The math would be: x + (-3) = -1, which solves to x = +2. Therefore, the oxidation number of tin (Sn) in SnCl₃⁻ is +2.
The oxidation numbers are as follows: tin (Sn) is +2, and each chlorine (Cl) atom is -1.