Medium INTEGER +4 / -1 PYQ · JEE Mains 2020

The oxidation states of iron atoms in compounds (A), (B) and (C), respectively, are x, y and z. The sum of x, y and z is ________.

Na4[Fe(CN)5(NOS)]
       (A)

Na4[FeO4]
       (B)

[Fe2(CO)9]
       (C)

Answer (integer) 6

Solution

Na<sub>4</sub>[Fe(CN)<sub>5</sub>(NOS)] <br><br>Let the O.S. of Fe be x <br><br>OS of CN = –1 <br>OS of NOS = –1 <br><br>$\therefore$ (+1)4 + x + (–1)5 + (–1)1 = 0 <br><br>$\Rightarrow$ x = +2 <br><br>Na<sub>4</sub>[FeO<sub>4</sub>] <br><br>Let O.S. of Fe be y <br><br>(+1)4 + y + (–2)4 = 0 <br><br>$\Rightarrow$ y = +4 <br><br>[Fe<sub>2</sub>(CO)<sub>9</sub>] <br><br>Let O.S. of Fe be z <br><br>2z + 0 × 9 = 0 <br><br>$\Rightarrow$ z = 0 <br><br>so (x + y + z) = +2 + 4 + 0 = 6

About this question

Subject: Chemistry · Chapter: Coordination Compounds · Topic: Ligands and Coordination Number

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