Question

Write the chemical name and formula of washing soda.Why is it called a basic salt? Explain with the help of chemical equations .

Answer 1

Hint: Try to recollect that the washing soda exists a decahydrate which is a white crystalline solid on heating the decahydrate will lose the water of crystallization and changes to a white powder named soda ash.

Complete Solution :
- The chemical name of washing soda is Sodium carbonate Decahydrate and the chemical formula is $N{{a}_{2}}C{{O}_{3}}.10{{H}_{2}}O$. The sodium carbonate is manufactured by Solvay-ammonia process and this method is based on the principle that when carbon dioxide is passed through sodium chloride ( brine) solution saturated with ammonia, after certain steps of purification, sodium carbonate will be formed.
- The washing soda is readily soluble in water and it reacts with dilute mineral acids and carbon dioxide is evolved. It's used for softening of hard water, used for washing purposes in laundry , as a reagent in laboratory and also used in the manufacture of glass, soap, caustic soda etc.
- Sodium carbonate is a basic salt because on hydrolysis it gives a strong base and weak acid as products. It can be explained with the following chemical equation:
\[N{{a}_{2}}C{{O}_{3}}+2{{H}_{2}}O\to \underset{strong\text{ }base}{\mathop{2NaOH}}\,+\underset{weak\text{ }acid}{\mathop{{{H}_{2}}C{{O}_{3}}}}\,\]
  Thus washing soda is a basic salt.

Note: Do not confuse between washing soda and baking soda, Even though both their names and formula are much similar , they have a small difference. Baking soda has a hydrogen atom and contains only one sodium atom($NaHC{{O}_{3}}$) while washing soda has no hydrogen atom and has two sodium atoms ($N{{a}_{2}}C{{O}_{3}}$).