Question

Chemical formula for ammonium chloride by criss cross method

Answer 1

valency of NH4 = 1
valency of Cl = 1
molecular formula for ammonium chloride by criss cross method :
NH4 - CL
=1 - 1
=0
Therefore, by criss cross method, we get the molecular formula of ammonium chloride.
I.e. NH4Cl

Answer 2

The chemical formula for ammonium chloride is $NH_{4}Cl$.

• The ammonium ion is formed when ammonia ($NH_{3}$) loses an electron to form a cation. This gives ammonia a valency of +1.
• Chloride anion is formed when chlorine gains an electron. The valency of chlorine is hence -1.
• While writing the chemical formula for ammonium chloride, we have to observe the valencies of both the ions.

• $NH_{4} ^{+}$ = +1 ; $Cl^{-}$ = -1
• On criss-crossing the valencies of both, we get-

         $NH_{4(1)}Cl_{(1)}$

• Ignoring the positive and negative signs, we write the chemical formula as- $NH_{4}Cl$.