Medium INTEGER +4 / -1 PYQ · JEE Mains 2022

Metal deficiency defect is shown by Fe0.93O. In the crystal, some Fe2+ cations are missing and loss of positive charge is compensated by the presence of Fe3+ ions. The percentage of Fe2+ ions in the Fe0.93O crystals is __________. (Nearest integer)

Answer (integer) 85

Solution

$\mathrm{Fe}_{0.93} \mathrm{O}$ <br/><br/> Let the number of $\mathrm{O}^{-2}$ ions be 100 and the number of $\mathrm{Fe}^{+2}$ ions be $\mathrm{X}$ The number of $\mathrm{Fe}^{+3}$ ions be $(93-\mathrm{X})$ <br/><br/> $$ \begin{aligned} &\therefore \,X(2)+(93-X) 3=200 \\\\ &279-X=200 \\\\ &X=79 \\\\ &\therefore \quad \% \text { of } F^{+2} \text { ions } =\frac{79}{93} \times 100 \\\\ &\simeq 85 \% \end{aligned} $$

About this question

Subject: Chemistry · Chapter: States of Matter · Topic: Gas Laws

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