Final answer:
When sodium bromide reacts with concentrated sulfuric acid, bromide ions are oxidized to bromine gas, and sulfuric acid is reduced, typically to sulfur dioxide gas. Sulfuric acid is an oxidizing agent that prevents the formation of hydrogen bromide gas in this process.
Step-by-step explanation:
When sodium bromide reacts with concentrated sulfuric acid, a redox reaction occurs. During the process, sulfuric acid acts as an oxidizing agent and oxidizes the bromide (Br⁻) ions to bromine gas (Br2), while the sulfuric acid is reduced, typically to sulfur dioxide (SO2) gas.
As sulfuric acid is a strong oxidizing agent, it is not favorable for the production of hydrogen bromide gas in this case, as it will further react with the bromide to form bromine gas. Instead, to produce hydrogen bromide, a weaker oxidizing acid like phosphoric acid should be used:
H3PO4(l) + Br⁻(aq) → HBr(g) + H2PO4⁻(aq)
Therefore, in the reaction of sodium bromide with concentrated sulfuric acid, expect the formation of bromine gas, water, and possibly sulfur dioxide, depending on the reaction conditions.