As an acid sulphur dioxide reacts with sodium hydroxide solution to form a salt called sodium sulphate Na2SO3 and water. Write a balanced chemical equation for the reaction (show state symbols)?

1 Answer
Apr 13, 2018

SO_2 (g)+2NaOH_((s))->Na_2SO_3(s)+H_2O_((l))

Explanation:

SO_2 + NaOH->Na_2SO_3 + H_2O

Now, a balanced equation of a reaction has equal atoms of each element on both sides. So we count the atoms each element.

  • We have 1 atom of Sulphur on the one side (SO_2) and 1 on the other side (Na_2SO_3).

  • We have 3 atoms of Oxygen on the one side (SO_2 and NaOH), but 4 on the other side (Na_2SO_3 and H_2O).

  • We have 1 atom of Sodium (NaOH), but 2 on the other side (Na_2SO_3).

  • We have 1 atom of Hydrogen (NaOH), but 2 on the other side (H_2O).

So to balance it:

SO_2 (g)+2NaOH_((s))->Na_2SO_3(s)+H_2O_((l))

SO_2 is a gas.
NaOH is a powder, which means its solid.
Na_2SO_3 is a salt in the form of a powder, which is solid.
H_2O is liquid, for obvious reasons.