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
$(i)$ $H _{2(g)}+ Cl _{2(g)} \longrightarrow 2 HCl _{(g)}$
$(ii)$ $3 BaCl _{2(s)}+ Al _{2}\left( SO _{4}\right)_{3(s)} \longrightarrow 3 BaSO _{4(s)}+2 AlCl _{3(s)}$
$(iii)$ $2 Na _{(s)}+2 H _{2} O _{(i)} \longrightarrow 2 NaOH _{(a q)}+ H _{2(g)}$
What is the difference between displacement and double displacement reactions ? Write equations for these reactions.
Why should a magnesium ribbon be cleaned before burning in air ?
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 do you mean by a precipitation reaction? Explain by giving examples.
Why do we apply paint on iron articles ?