Final answer:
Efficiency, in terms of drying agents, is the effectiveness of a drying agent to absorb moisture, represented by the energy absorbed divided by the total energy input. Useful work is the moisture removed, and the efficiency is never 100% due to inevitable energy loss.
Step-by-step explanation:
In the context of drying agents, efficiency refers to the measure of how effectively a drying agent can absorb moisture. It is the fraction of the input energy, in this case the energy of the water or moisture, that can be absorbed and held by the drying agent, converting it to useful work. Useful work here is the successful removal of water or other solvents from a substance during the drying process. When considering energy, efficiency can be expressed as Eff = Wout / Ein, where Wout is the useful work output (amount of moisture absorbed) and Ein is the energy consumed (capacity of the drying agent to bind water).
Surfactants, often found in laundry detergent, work under the same principle of efficiency. They are effective due to their ability to emulsify soils and reduce the water's surface tension to improve wetting, thereby enhancing the drying efficiency. An ideal efficiency, known as 100 percent or an efficiency of 1, would mean that the drying agent could absorb moisture without any energy loss to the environment. However, in practical scenarios, some energy is always lost, mainly as thermal energy, thus full efficiency is never achieved.