How do you balance the following chemical equations by adding coefficients?

$H C I \to {H}_{2} O + N a C I$ $F {e}_{2} {O}_{3} + C \to F e + C {O}_{2}$ SO_2 + O_2 -> SO_3#

Apr 27, 2016

You do so stoichiometrically. Garbage out must equal garbage in.

Explanation:

$H C l \left(a q\right) + N a O H \left(a q\right) \rightarrow N a C l \left(a q\right) + {H}_{2} O \left(l\right)$
(I am guessing that this is the equation you mean.)

$2 F {e}_{2} {O}_{3} \left(s\right) + 3 C \left(s\right) \rightarrow 4 F e \left(l\right) + 3 C {O}_{2} \left(g\right)$
(This is the reaction that would take place in an iron foundry.)

$S {O}_{2} \left(g\right) + \frac{1}{2} {O}_{2} \rightarrow S {O}_{3} \left(g\right)$
(You can double this equation if you dislike the fractional coefficient.)

Are all equations stoichiometrically balanced? If not, they should be.