This question is about transition metals, oxides of iron, and differences in lattice structures of oxides.
Iron forms several oxides including FeO\text{FeO}FeO, Fe2O3\text{Fe}_2\text{O}_3Fe2O3, and Fe3O4\text{Fe}_3\text{O}_4Fe3O4.
A student carries out an experiment to identify an unknown iron oxide by reducing it to iron metal. The student heats the unknown iron oxide in a horizontal tube in a stream of hydrogen gas, H2\text{H}_2H2.
Student's method:
Write the balanced equation for the reduction of Fe3O4\text{Fe}_3\text{O}_4Fe3O4 with H2\text{H}_2H2 to form iron and steam.
The student wears safety glasses and a lab coat. State, with a reason, one other important safety precaution the student should take when carrying out this experiment involving hydrogen.
Suggest two modifications that the student could make to their method to be confident that all the oxygen had been removed from the iron oxide. Explain your reasoning.
After making suitable modifications, the student repeats the experiment to obtain the following accurate results:
Calculate the empirical formula of the iron oxide.
SiO2\text{SiO}_2SiO2 and SO2\text{SO}_2SO2 are acidic oxides. Solid SiO2\text{SiO}_2SiO2 melts at 1713 ∘C1713\text{ }^\circ\text{C}1713 ∘C while solid SO2\text{SO}_2SO2 melts at −72 ∘C-72\text{ }^\circ\text{C}−72 ∘C.
Suggest the type of lattice structure in solid SiO2\text{SiO}_2SiO2 and in solid SO2\text{SO}_2SO2, and explain the difference in melting points in terms of the types of force within each lattice structure.
