Balance the following chemical equations.

$(a)$ $HNO _{3}+ Ca ( OH )_{2} \longrightarrow Ca \left( NO _{3}\right)_{2}+ H _{2} O$

$(b)$ $NaOH + H _{2} SO _{4} \longrightarrow Na _{2} SO _{4}+ H _{2} O$

$(c)$ $NaCl + AgNO _{3} \longrightarrow AgCl + NaNO _{3}$

$(d)$ $BaCl _{2}+ H _{2} SO _{4} \longrightarrow BaSO _{4}+ HCl$

What happens when dilute hydrochloric acid is added to iron fillings ? Tick the correct answer.

Which of the statements about the reaction below are incorrect ?

$2 PbO _{( s )}+ C _{( s )} \longrightarrow 2 Pb _{( s )}+ CO _{2( g )}$

$(a)$ Lead is getting reduced.

$(b)$ Carbon dioxide is getting oxidised.

$(c)$ Carbon is getting oxidised.

$(d)$ Lead oxide is getting reduced.

What does one mean by exothermic and endothermic reactions ? Give examples.

A solution of a substance $‘X’$ is used for whitewashing.

$(i)$ Name the substance $‘X’$ and write its formula.

$(ii)$ Write the reaction of the substance $‘X’$ named in $(i)$ above with water.

Explain the ''Corrosion'' terms with one example.