What is meant by a skeletal chemical equation?

Identify the oxidising agent (oxidant) in the following reactions:
$(a) Pb_{3}O_{4} + 8HCl \longrightarrow 3PbCl_{2} + Cl_{2} + 4H_{2}O$
$(b) 2Mg + O_{2} \longrightarrow 2MgO$
$(c) CuSO_{4} + Zn \longrightarrow Cu + ZnSO_{4}$
$(d) V_{2}O_{5} + 5Ca \longrightarrow 2V + 5CaO$
$(e) 3Fe + 4H_{2}O \longrightarrow Fe_{3}O_{4} + 4H_{2}$
$(f) CuO + H_{2} \longrightarrow Cu + H_{2}O$

$(a)$ Define corrosion.
$(b)$ What is corrosion of iron called?
$(c)$ How will you recognise the corrosion of silver?

Identify the type of reactions in each of the following reactions:
$(i)$ $CaCO_{3} \xrightarrow{\text{Heat}} CaO + CO_{2}$
$(ii)$ $AgNO_{3}(aq) + NaCl(aq) \longrightarrow AgCl(s) \downarrow + NaNO_{3}(aq)$

In which of the following chemical equations,the abbreviations represent the correct states of the reactants and products involved at reaction temperature?

Which of the following statements about the given reaction are correct?
$3 Fe (s) + 4 H_2 O (g) \rightarrow Fe_3 O_4 (s) + 4 H_2 (g)$
$(i)$ Iron metal is getting oxidised
$(ii)$ Water is getting reduced
$(iii)$ Water is acting as reducing agent
$(iv)$ Water is acting as oxidising agent