<p>When SN(IV) chloride is treated with excess HCl, the complex&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><msup><mfenced open="[" close="]"><msub><mi>SnCl</mi><mn>6</mn></msub></mfenced><mrow><mn>2</mn><mo>-</mo></mrow></msup></math>&nbsp;is formed. The oxidation state of Sn in this complex is:</p>