When added to water, which of the following would produce a base?

SO2

NO2

K2O

CO2

Reaction of water with K₂O produce base.

Explanation:

Reaction of water with K₂O:

K₂O + H₂O → 2KOH

when potassium oxide react with water it produces potassium hydroxide which is base.

Reaction of water with carbondioxide:

When carbondioxide react with water it produces carbonic acid.

CO₂ + H₂O → H₂CO

Carbonic acid is a weak acid and dissociate to gives H⁺ ions. It is aslightly acidic solution and convert into hydrocarbonate ions.

H₂CO₃ → H⁺ + HCO⁻₃

HCO⁻₃ → H⁺ + CO₃⁻²

Reaction of water with NO₂:

3NO₂ + H₂O → 2HNO₃ + NO

Nitrogen dioxide react with water and produce nitric acid and nitrogen monoxide.

Reaction of water with SO₂:

SO₂ + H₂O → H₂SO₃

When sulfur dioxide react with water it gives sulfurous acid.