Question

An element is placed in the 2nd Group and 3rd Period of the Periodic Table and burns in presence of oxygen to form a basic oxide. (d) Write a balanced equation when this oxide is dissolved in water

Answer 1

Element in 2nd group and 3rd period

• The element present in the 2nd group and 3rd period is Magnesium.
• The symbol for magnesium is $\mathrm{Mg}$.

Chemical reaction between Magnesium oxide and water:

• When magnesium is burnt in the air, the formation of Magnesium oxide$\left(\mathrm{MgO}\right)$ takes place.
• When Magnesium oxide reacts with water, the formation of Magnesium hydroxide takes place.
• The reaction of $\mathrm{MgO}$ with water is as follows:-
• $$\begin{gathered} \mathrm{MgO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{Mg}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right) \\ \mathrm{Magnesium}\mathrm{oxide}\mathrm{Water}\mathrm{Magnesium}\mathrm{hydroxide} \end{gathered}$$