Metal deficiency defect is shown by $$Fe_{0.93}O$$. In the crystal, some $$Fe^{2+}$$ cations are missing and loss of positive charge is compensated by the presence of $$Fe^{3+}$$ ions. The percentage of $$Fe^{2+}$$ ions in the $$Fe_{0.93}O$$ crystals is ______ (Nearest integer)

In the crystal $$Fe_{0.93}O$$, some $$Fe^{2+}$$ ions are missing and replaced by $$Fe^{3+}$$ ions to maintain electrical neutrality.

Let us assume that in the formula $$Fe_{0.93}O$$, let $$x$$ be the number of $$Fe^{3+}$$ ions and $$(0.93 - x)$$ be the number of $$Fe^{2+}$$ ions per formula unit.

Charge balance:

The total positive charge must equal the total negative charge.

Charge from $$Fe^{2+}$$: $$2(0.93 - x)$$

Charge from $$Fe^{3+}$$: $$3x$$

Charge from $$O^{2-}$$: $$-2(1) = -2$$

For electrical neutrality:

$$2(0.93 - x) + 3x = 2$$

$$1.86 - 2x + 3x = 2$$

$$1.86 + x = 2$$

$$x = 0.14$$

So, number of $$Fe^{3+}$$ ions = 0.14

Number of $$Fe^{2+}$$ ions = $$0.93 - 0.14 = 0.79$$

Percentage of $$Fe^{2+}$$ ions:

$$\% Fe^{2+} = \frac{0.79}{0.93} \times 100$$

$$= \frac{79}{93} \times 100$$

$$= 84.95\%$$

$$\approx 85\%$$

Hence, the percentage of $$Fe^{2+}$$ ions is 85 (nearest integer).