Question

The step by step experiment to determine the cubic expansivity of a liquid

Answer 1

In accordance with the definition of density as r = m/V, in order to determine the density of matter, the mass and the volume of the sample must be known. The determination of mass can be performed directly using a weighing instrument. The determination of volume generally cannot be performed directly. Exceptions to this rule include · cases where the accuracy is not required to be very high, and · measurements performed on geometric bodies, such as cubes, cuboids or cylinders, the volume of which can easily be determined from dimensions such as length, height and diameter. · The volume of a liquid can be measured in a graduated cylinder or in a pipette; the volume of solids can be determined by immersing the sample in a cylinder filled with water and then measuring the rise in the water level. Because of the difficulty of determining volume with precision, especially when the sample has a highly irregular shape, a "detour" is often taken when determining the density, by making use of the Archimedean Principle, which describes the relation between forces (or masses), volumes and densities of solid samples immersed in liquid: From everyday experience, everyone is familiar with the effect that an object or body appears to be lighter than in air – just like your own body in a swimming pool. Figure 3: The force exerted by a body on a spring scale in air (left) and in water (right)