Final answer:
The oxidation number of Pt in the compound H2PtCl6 is +4. This is determined through the charges of hydrogen and chlorine, considering the overall charge of the compound must equal zero.
Step-by-step explanation:
The question asks to find the oxidation number of Pt in the compound H2PtCl6. We start by understanding the charge on each ion within the compound. H2 represents two hydrogen ions with a total charge of +2 because each hydrogen has an oxidation number of +1. Since the overall molecule is neutral and Cl is usually -1, we can set up an equation:
2(+1) + x + 6(-1) = 0
Where x is the oxidation state of Pt. Simplifying this we get:
2 - 6 + x = 0
x = 4
Therefore, the oxidation number of Pt in H2PtCl6 is +4.