Answer:
Sodium sulfite (Na2SO3)
Explanation:
Sulfuric acid is able to displace volatile acids from their corresponding salts and the acids displaced are unstable and they break down to give volatile products
For example, in to reaction of sulfuric acid and sodium sulfite; two processes occur
1. Sulfuric acid forms sodium sulfate and sulfurous acid
Na2SO3(s) + H2SO4(aq) -------> Na2SO4(aq) + H2SO3
2. The H2SO3 is unstable thereby decompose spontaneously to water and sulfur dioxide gas.
H2SO3 -----------> H2O(l) + SO2(g)
Final reaction gives;
Na2SO3(s) + H2SO4 (aq) ---------> Na2SO4(aq) + H2O(l) + SO2(g)