What does the polystyrene cup's design help achieve in the experiment?

The design of a polystyrene cup is particularly beneficial for achieving better heat retention during experiments. Polystyrene is an excellent insulator, meaning it does not allow heat to pass through easily. When used as a container for reactions, this property helps maintain the temperature of the contents, preventing heat loss to the surrounding environment.

In experiments where temperature changes are critical, such as those measuring reaction rates or energy changes, it's essential to keep the heat inside the container. Polystyrene cups are often employed in calorimetry for this reason; they help ensure that the heat generated or absorbed during the reaction is accurately measured, leading to more reliable results. This insulating quality is what makes the polystyrene cup an effective choice for experiments that require precise temperature control.