Saturated hydrocarbons with a carbon chain length in the range of [tex]\(17-35\)[/tex] are the best lubricants.
To determine the best range of carbon chain lengths for lubricants, we consider the different options provided:
1. [tex]\(1-2\)[/tex]: This range includes very short-chain hydrocarbons. Typically, these are gases or very light liquids at room temperature and are not effective as lubricants because they lack enough molecular size to form a stable, lubricating film between surfaces.
2. [tex]\(5-8\)[/tex]: Hydrocarbons in this range are also relatively short. They might be better than [tex]\(1-2\)[/tex] chain length hydrocarbons because they can form a more substantial film. However, they are generally too volatile to provide consistent lubrication under a wide range of conditions.
3. [tex]\(17-35\)[/tex]: Hydrocarbons in this range are long enough to form stable, viscous films that adhere well to surfaces. They are well-regarded for their ability to maintain a lubricating layer and reduce wear and friction effectively. Hence, they provide good lubrication properties.
4. More than 35: While these longer-chain hydrocarbons can be effective in some cases, they tend to be too viscous, thick, or even solid at room temperature. This can make them less practical as lubricants under typical operating conditions, leading to difficulties in application and potentially causing higher friction than desired during the operation.
Therefore, the best range of carbon chain lengths for lubricants is [tex]\(17-35\)[/tex].
