How many moles of Fe2O3 are contained in 1kg of the compound? Fe=56,O=16

The atomic mass of Fe is 56 g/mol.
The atomic mass of O is 16 g/mol.

$$\text{Molar mass of } \text{Fe}_2\text{O}_3 = (2 \times \text{atomic mass of Fe}) + (3 \times \text{atomic mass of O})$$ $$\text{Molar mass of } \text{Fe}_2\text{O}_3 = (2 \times 56 \text{ g/mol}) + (3 \times 16 \text{ g/mol})$$ $$\text{Molar mass of } \text{Fe}_2\text{O}_3 = 112 \text{ g/mol} + 48 \text{ g/mol}$$ $$\text{Molar mass of } \text{Fe}_2\text{O}_3 = 160 \text{ g/mol}$$

$$\text{Moles} = \frac{\text{Mass}}{\text{Molar mass}}$$ $$\text{Moles of } \text{Fe}_2\text{O}_3 = \frac{1000 \text{ g}}{160 \text{ g/mol}}$$ $$\text{Moles of } \text{Fe}_2\text{O}_3 = 6.25 \text{ mol}$$

The number of moles of $\text{Fe}_2\text{O}_3$ in 1 kg of the compound is $\boxed{\text{6.25 mol}}$.