Explanation:

A eudiometer is a laboratory device that measures the change in volume of a gas mixture following a physical or chemical change.Depending on the reaction being measured, the device can take a variety of forms. In general, it is similar to a graduated cylinder, and is most commonly found in two sizes: 50 mL and 100 mL. It is closed at the top end with the bottom end immersed in water or mercury. The liquid traps a sample of gas in the cylinder, and the graduation allows the volume of the gas to be measured. For some reactions, two platinum wires (chosen for their non-reactivity) are placed in the sealed end so an electric spark can be created between them. The electric spark can initiate a reaction in the gas mixture and the graduation on the cylinder can be read to determine the change in volume resulting from the reaction. The use of the device is quite similar to the original barometer, except that the gas inside displaces some of the liquid that is used.