Answer:
PbSO₃(s)⟶PbO(s)+SO₂(g)
Explanation:
In order for an equation to be balanced, both the charges and the masses need to be the same in both sides of the equation.
In the case of the reaction PbSO₃(s)⟶PbO(s) +SO₂(g), there are no charges in either side, so it is already electronically balanced.
Regarding masses, let's see each element one by one:
Pb ⇒ There's 1 Pb in both sides already.
S ⇒ There's 1 S in both sides already.
O ⇒ There're 3 O in both sides already.
So the equation is balanced as is.