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.

A shiny brown coloured element $‘X’$ on heating in air becomes black in colour. Name the element $‘X’$ and the black coloured compound formed.

What is the difference between displacement and double displacement reactions ? Write equations for these reactions.

Why is respiration considered an exothermic reaction ? Explain.

Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.

Write the balanced equation for the following chemical reactions.

$(i)$ Hydrogen $+$ Chlorine $\to $ Hydrogen chloride

$(ii)$ Barium chloride $+$ Aluminium sulphate $\to $ Barium sulphate $+$ Aluminium chloride

$(iii)$ Sodium $+$ Water $\to $  Sodium hydroxide $+$ Hydrogen