What is equivalent to 100 ppm for a gas with a molecular weight of 24.45 in mg/m3?

To understand why 100 ppm is equivalent to 100 mg/m³ for a gas with a molecular weight of 24.45, it is essential to grasp the relationship between parts per million (ppm), molecular weight, and concentration in milligrams per cubic meter (mg/m³).

PPM refers to the number of parts of a substance per million parts of a total, and it is often used in regard to gases. The concentration in mg/m³ can be calculated using the molecular weight of the gas involved in the calculation.

The formula to convert ppm to mg/m³ is given by:

[ \text{Concentration (mg/m³)} = \frac{\text{ppm} \times \text{Molecular Weight}}{24.45} ]

Here, the term 24.45 represents the molar volume of a gas at standard temperature and pressure, approximating the volume of one mole of gas in liters.

Substituting 100 ppm into the formula:

[ \text{Concentration (mg/m³)} = \frac{100 \times 24.45}{24.45} = 100 , \text{mg/m³} ]

This identifies that at 100 ppm, the concentration indeed