Write equations for the reactions of
$(i)$ iron with steam
$(ii)$ calcium and potassium with water
$(i)$ $\underset{Iron}{\mathop{3F{{e}_{(s)}}}}\,\,+\,\underset{Steam}{\mathop{4{{H}_{2}}{{O}_{(g)}}}}\,\,\to \,\underset{Iron\,(II,III)\,oxide}{\mathop{F{{e}_{3}}{{O}_{4(aq)}}}}\,\,+\underset{Hydrogen}{\mathop{\,4{{H}_{2(g)}}}}\,$
$(ii)$ $C{{a}_{(s)}}+2{{H}_{2}}{{O}_{(l)}}\to Ca{{(OH)}_{2(aq)}}$ $+{{H}_{2(g)}}+\text{ Heat }$
$(iii)$$\underset{\begin{smallmatrix}
\text{Calcium}\,\text{/} \\
\text{Potassium}
\end{smallmatrix}}{\mathop{2{{K}_{(s)}}}}\,+\underset{water}{\mathop{2{{H}_{2}}{{O}_{(l)}}}}\,\to \underset{\begin{smallmatrix}
\text{Calcium Hydroxide /} \\
\text{Potassium hydroxide}
\end{smallmatrix}}{\mathop{2KO{{H}_{(aq)}}}}\,+\underset{Hydrogen}{\mathop{{{H}_{2(g)}}}}\,+\text{ Heat }$
Food cans are coated with tin and not with zinc because
You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
What would you observe when zinc is added to a solution of iron $(II) $ sulphate ? Write the chemical reaction that takes place.
What type of oxides are formed when non-metals combine with oxygen?
Why do ionic compounds have high melting points ?