What information is needed to estimate the concentration of a vapor?

To accurately estimate the concentration of a vapor, both the temperature and molar mass of the substance are crucial pieces of information.

The temperature plays a significant role because it affects the vapor pressure of the substance, which is a measure of how readily a liquid turns into its gaseous phase. As temperature increases, the vapor pressure typically increases as well, meaning more molecules can escape into the air, thereby increasing vapor concentration. This relationship is often described by Raoult's law and other gas laws, which illustrate how temperature impacts vapor concentrations.

Molar mass is equally important since it directly influences the calculation of concentration based on moles of vapor in a given volume of air. The concentration can be expressed in terms of moles per unit volume; thus, knowing the molar mass allows one to convert between the mass of the vapor present and the number of moles, which is essential for more complex calculations related to toxicology and exposure limits.

In terms of the other options, the molar mass alone would not provide enough context for estimating vapor concentration without temperature, nor would temperature alone suffice, as the relationship between vapor concentration and molecular weight is important for accurate calculations. The ventilation rate alone is also insufficient because it does not provide information about the vapor