SAChE Toxicological Hazards Practice Test 2026 – Complete Exam Prep

To determine the maximum concentration of a chemical that evaporates from 2 grams in a storage room of 20 m³ at 20°C, it is crucial to understand the relationship between mass, volume, and concentration.

First, we need to convert the mass of the chemical (2 grams) into a concentration in terms of parts per million by volume (ppmv). Concentration in ppmv can be calculated using the formula:

Concentration (ppmv) = (mass of substance in grams / molecular weight of substance) / (volume of air in liters) × 10^6.

However, if we simplify the approach by considering the volume of the room:

1. We convert the room volume from cubic meters to liters:

20 m³ = 20,000 liters (since 1 m³ = 1,000 liters).

2. Next, we convert grams to milligrams since one gram is equal to 1,000 milligrams:

2 grams = 2,000 mg.

3. We can then calculate the concentration by taking the amount of the evaporated chemical (2,000 mg) and dividing it by the volume of air (20,000 liters):

Concentration (mg/m³)