CAIE IGCSE Chemistry Identifying Redox by Oxygen Transfer

$\mathrm{AgNO}_{3}+\mathrm{NaCl} \rightarrow \mathrm{AgCl}+\mathrm{NaNO}_{3}$

$\mathrm{PCl}_{5}+4 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{H}_{3} \mathrm{PO}_{4}+5 \mathrm{HCl}$

$3 \mathrm{Fe}+4 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Fe}_{3} \mathrm{O}_{4}+4 \mathrm{H}_{2}$

$\mathrm{MgCO}_{3}+2 \mathrm{HCl} \rightarrow \mathrm{MgCl}_{2}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}$