An ==Key Stage 3=====Meaning===[[Sulphurous Acid]] is an [[acid]] made of 1 with the [[SulphurChemical Formula|chemical formula]], H<sub>2</sub>SO<sub>3 </sub>.''NB: Not to be confused with [[Sulphuric Acid]].'' ===About Sulphurous Acid===: [[Sulphurous Acid]] is a weak [[Oxygenacid]] and 2 but does not exist in [[Hydrogensolution]] , only as a [[Atom|atomsgas]].