One mole of a non-stoichiometric metal oxide M_xO (where M exists as M²⁺ and M³⁺ ) is completely oxidized to M³⁺ by 0.17 moles of acidified KMnO ₄ . The value of x 100 is ______.

Step-by-step solution

The oxidation of M_xO to M³⁺ involves the oxidation of M²⁺ to M³⁺ . Let the number of moles of M²⁺ in 1 mole of M_xO be a and the number of moles of M³⁺ be b . The n-factor of M_xO is equal to the number of moles of electrons lost per mole of the compound, which is exactly a (since each M²⁺ loses 1 electron). In an acidic medium, the n-factor of KMnO ₄ is 5. Equivalents of KMnO ₄ used = 0.17 5 = 0.85 . By the law of equivalence, equivalents of M_xO = equivalents of KMnO ₄ . Since we have 1 mole of M_xO , its n-fact