Find the ratio by mass of the combining elements in the compound ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$.

Find the ratio by mass of the combining elements in the compound ${\mathrm{NH}}_3$

Find the ratio by mass of the combining elements in the compound $\mathrm{Ca}(\mathrm{OH}{)}_2$.

Calcium chloride, when dissolved in water, dissociates into its ions according to the following equation:

 ${\mathrm{CaCl}}_2\left(\mathrm{aq}\right)\to {\mathrm{Ca}}^{2+} \left(\mathrm{aq}\right) + 2{\mathrm{Cl}}^{-} \left(\mathrm{aq}\right)$

Calculate the number of ions obtained from CaCl₂ when 222 g of it is dissolved in water.

Raunak took $5$ moles of carbon atoms in a container and Krish also took $5$ moles of sodium atoms in another container of same weight.

Whose container is heavier?