Q. What is the classification for this balanced reaction Zn(s) H2SO4(aq) → ZnSO4(aq) + H2(g)

The reaction Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g) is classified as a single replacement reaction (single displacement reaction) and simultaneously as a redox reaction. In this reaction, zinc metal replaces hydrogen from sulfuric acid, forming zinc sulfate and hydrogen gas. The single replacement pattern is evident: one element (Zn) displaces another element (H) from a compound (H2SO4), leaving the displaced element as a free substance (H2).

From a redox perspective, zinc is oxidized (loses electrons, going from 0 to +2 oxidation state) and hydrogen is reduced (gains electrons, going from +1 in the acid to 0 in H2 gas). This type of reaction is characteristic of active metals reacting with acids, following the general pattern: metal + acid → salt + hydrogen gas. The reaction is exothermic and produces visible hydrogen gas bubbling, making it a common demonstration in chemistry education. This reaction also represents a specific subclass called metal-acid reactions, which always produce a salt (in this case, zinc sulfate) and hydrogen gas when a metal that's more active than hydrogen reacts with an acid. The dual classification as both single replacement and redox helps predict the products and understand the electron transfer mechanism driving the reaction.