The following reaction is an example of a:
$4 NH_{3}(g) + 5 O_{2}(g) \longrightarrow 4 NO(g) + 6 H_{2}O(g)$
$(i)$ displacement reaction
$(ii)$ combination reaction
$(iii)$ redox reaction
$(iv)$ neutralisation reaction

On heating blue coloured powder of copper $(II)$ nitrate in a boiling tube,copper oxide (black),oxygen gas and a brown gas $X$ is formed.
$(a)$ Write a balanced chemical equation of the reaction.
$(b)$ Identify the brown gas $X$ evolved.

Why do we store silver chloride in dark-coloured bottles?

Which among the following statement$(s)$ is(are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to
$(i)$ the formation of silver by decomposition of silver chloride
$(ii)$ sublimation of silver chloride
$(iii)$ decomposition of chlorine gas from silver chloride
$(iv)$ oxidation of silver chloride

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

Write two observations for the following chemical reaction:
$(a)$ Lead nitrate is strongly heated in a hard glass test tube.