The gas generated on reacting zinc with dilute sulphuric acid is:

When zinc metal reacts with dilute sulphuric acid, it undergoes a single displacement reaction to produce zinc sulphate and hydrogen gas [1]. Zinc, being more reactive than hydrogen, displaces hydrogen from the acid. The chemical equation for this reaction is Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g). This process is a traditional laboratory method for generating small amounts of hydrogen gas. The evolution of the gas is typically observed as effervescence or bubbles. While concentrated sulphuric acid can act as an oxidizing agent and produce sulphur dioxide, the reaction with the dilute form specifically liberates hydrogen. Other gases like argon, helium, and nitrogen are inert or unrelated to this specific metal-acid chemical change.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 1: Chemical Reactions and Equations > Figure 1.2 > p. 2