The acid and alkali that would react to make sodium sulfate is
alkali= sodium hydroxide
acid = sulphuric acid
explanation
Acid react react with alkali to form salt and water.
For sodium sulfate salt to be formed a sulfate acid is required to react with a hydroxide of sodium .
therefore Sodium hydroxide (alkali) react with sulphuric acid (an acid) to form sodium sulfate (salt) and water.
