Question

3. Two equations below look like they are balanced, and they are, but the coefficients are wrong
nevertheless. In one sentence explain what is wrong with them, and rewrite them so that the
coefficients are correct.

2 Mg(OH)2(s) + 4 HCl(aq) → 2 MgCl2(aq) + 4 H2O(l)


C3H6(g) + 4.5 O2(g) → 3 CO2(g) + 3 H2O(g)

Answer 1

Mg(OH)2(s) + 2 HCl(aq) → MgCl2(aq) + 2 H2O(l)

2C3H6(g) + 9 O2(g) → 6 CO2(g) + 6 H2O(g)
The first equation doesn't have the simplest coefficients. The second equation has a fraction and not whole numbers. By the way, in some situations, especially in thermodynamics, it is permissible to use fractions.