Medium Practice — Set 1

Quick Recap — Oxidation States & Magnetism Calculations

• Spin-only moment: $\mu=\sqrt{n(n+2)}$ BM: $n=1\to1.73$, $2\to2.83$, $3\to3.87$, $4\to4.90$, $5\to5.92$.
• Unpaired electrons: $Ti^{3+}(d^1)=1$, $V^{2+}(d^3)=3$, $Cr^{3+}(d^3)=3$, $Mn^{2+}/Fe^{3+}(d^5)=5$, $Fe^{2+}(d^6)=4$, $Co^{2+}(d^7)=3$, $Ni^{2+}(d^8)=2$, $Cu^{2+}(d^9)=1$.
• $Cr_2O_7^{2-}\rightleftharpoons2CrO_4^{2-}$: orange (acid) $\leftrightarrow$ yellow (base).
• $d^0$/$d^{10}$ ions are colourless.