Which of the following substances will not give carbon dioxide on treatment with dilute acid?
Marble
Limestone
Baking soda
Lime
Steps: Marble, limestone (CaCO₃) and baking soda (NaHCO₃) react with dilute acids to give CO₂. Lime (CaO) does not give CO₂ with dilute acid (it forms soluble Ca²⁺ and water). Hence lime.