Option 1: The reaction of zinc metal with dilute sulphuric acid solution does result in the evolution of hydrogen gas. When zinc metal reacts with dilute sulphuric acid, zinc sulphate and hydrogen gas are produced.

Option 2: Mixing water to Plaster of Paris does not result in the evolution of hydrogen gas. Plaster of Paris is a compound composed of calcium sulfate hemihydrate. When water is added to Plaster of Paris, it undergoes a chemical reaction called hydration, where it absorbs water and forms gypsum. This reaction does not produce hydrogen gas.

Option 3: Heating zinc metal with sodium hydroxide solution results in the evolution of hydrogen gas. When zinc metal is heated with sodium hydroxide, zincate ions and hydrogen gas are produced.

Option 4: The reaction of potassium metal with water does result in the evolution of hydrogen gas. When potassium reacts with water, it undergoes a vigorous reaction, producing potassium hydroxide and hydrogen gas.

Therefore, option 2, mixing water to Plaster of Paris, is the correct answer as it does not result in the evolution of hydrogen gas.