The oxidation state of phosphorus in is: — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

**Step 1:** $Ba$ is an alkaline earth metal, so its oxidation state is +2. <br>**Step 2:** The $H_2PO_2$ group must have a net charge of -1. <br>**Step 3:** In $H_2PO_2^-$, let the O.S. of P be $x$: $2(+1) + x + 2(-2) = -1$. <br>**Step 4:** $2 + x - 4 = -1 \Rightarrow x - 2 = -1 \Rightarrow x = +1$.