Year 5 pupils investigated how different solids react when mixed with white vinegar. They added vinegar to bicarbonate of soda and a range of other solids, making careful observations throughout the investigation. Pupils observed bubbles being produced and identified that a gas was released. Through discussion, they learned that a chemical reaction had occurred, resulting in the formation of a new substance, carbon dioxide gas. They also understood that this was an irreversible change, as the original materials could not be recovered.