Write the chemical name of \(\mathrm{Na}_{2} \mathrm{CO}_{3} \cdot 10 \mathrm{H}_{2} \mathrm{O}\) and \(\mathrm{Na}_{2} \mathrm{CO}_{3} .\) Write the significance of \(\mathrm{1} 0 \mathrm{H}_{2} \mathrm{O}\). Mention the term used for water molecules attached with a salt. With the help of a chemical equation explain the method of preparation of both \(\mathrm{Na}_{2} \mathrm{CO}_{3} \cdot 10 \mathrm{H}_{2} \mathrm{O}\) and \(\mathrm{Na}_{2} \mathrm{CO}_{3}\). Also list two uses of \(\mathrm{Na}_{2} \mathrm{CO}_{3} \cdot 10 \mathrm{H}_{2} \mathrm{O}\).