Question

What is formality? Explain with examples.

Answer 1

Hint: The number of gram formula masses of the ionic solute dissolved per litre of solution is known as the formality of the solution. It is symbolised by $F$. The term formality is commonly used to describe the concentration of ionic solids, which are made up of a network of ions rather than molecules. Formal solution is a solution with a formality of one and contains one gramme formula mass of solute per litre of solution.

Complete answer:
Moles of solute per litre of solution are expressed by both molarity and formality. The overall concentration of a material in solution, regardless of its chemical structure, is known as formality. When \[0.1{\text{ }}mol\] of \[NaCl\] is dissolved in \[1{\text{ }}L\] of water, the result is a solution containing \[0.1{\text{ }}mol\] of \[N{a^ + }\,and{\text{ }}0.1\] mol of \[C{l^ - }\]. Because there is basically no undissociated \[NaCl\] in solution, the molarity of\[NaCl{\text{ }}is{\text{ }}0\]. Instead, the solution is \[0.1{\text{ }}M{\text{ }}Na + {\text{ }}and{\text{ }}0.1{\text{ }}M{\text{ }}Cl-.{\text{ }}NaCl\], on the other hand, has a formality of \[0.1{\text{ }}F\].
The number of formula masses of any solute dissolved in \[1{\text{ }}litre\] is the formality of the solution.

Note:
Let us know some more things about formality. The concentration of a specific chemical species is referred to as molarity. Formality, on the other hand, is the overall concentration of a substance, regardless of its chemical form. If a chemical dissolves without dissociating into ions, its molarity and formality are irrelevant.