2HCl(aq) + ZnS(s) ⇒ ZnCl₂(aq) + H₂S(g)
Equalization of chemical reactions can be done using variables. Steps in equalizing the reaction equation:
Reaction
HCl(aq) + ZnS(s) ⇒ ZnCl₂(aq) + H₂S(g)
1. give equation
aHCl(aq) + bZnS(s) ⇒ ZnCl₂(aq) + cH₂S(g)
2. make an equation
H, left=a, right=2c⇒a=2c(eq 1)
Cl, left=a, right=2⇒a=2⇒c=1(from eq 1)
Zn, left=b, right=1⇒b=1
So the equation :
2HCl(aq) + ZnS(s) ⇒ ZnCl₂(aq) + H₂S(g)