Question

Write down the chemical formula of:
Sodium nitrite

Answer 1

Hint:To write the chemical formula of Sodium Nitrate, we need to write the number of valence electrons, exchange it with corresponding compound and then write it as the subscript. Sodium Nitrate is formed by ionic interaction, that is, bond between Na (\[ + 1\]) ions and \[N{O_3}\left( { - 1} \right)\] ions.

Complete answer:
To write the chemical formula first we need to write down the symbol of every element or ion which combine to form a molecule of the compound side by side. While writing the formula of a compound containing a metal and a non-metal, the symbol of the metal is written first followed by that of the non-metal. We need to note here that two metals do not join up to form compounds. Then write the number of valence electrons of each element/ion. Interchange the valencies of the elements and write as the subscript. Write them close together and ignore 'l' to obtain the formula. The radical polyatomic ions must be written in brackets before the subscript is written. In case the number of polyatomic ions is one, the bracket is not required. Whenever applicable write simple ratios of the valencies. In the end, the final formula must be written without any sign of charge.
By following these steps, we get that Na is the symbol of sodium and \[N{O_2}\] is a formula for nitrite. Combining the two we get the formula of Sodium nitrite as \[NaN{O_2}\].

Note:
Sodium nitrate is a white solid which is very soluble in water. It is a readily available source of the nitrate anion (\[N{O_3}^ - \]), which is useful in several reactions carried out on industrial scales for the production of fertilizers, pyrotechnics and smoke bombs, glass and pottery enamels, food preservatives (esp. Meats), and solid rocket propellant. It has been mined extensively for these purposes.