Question

Section 1.7 showed that in 1997 los angeles county air had carbon monoxide (co) levels of 15.0 ppm. an average human inhales about 0.50 l of air per breath and takes about 20 breaths per minute. how many milligrams of carbon monoxide does the average person inhale in an 7 hour period for this level of carbon monoxide pollution? assume that the carbon monoxide has a density of 1.2 g/l. (hint: 15.0 ppm co means 15.0 lco per 106l air.)

Answer 1

75.6 mg

First calculate how many liters of air an average person will breath. We have 0.5 l per breath, times 20 breaths per minute, times 60 minutes per hour, times 7 hours. 0.50 l * 20 * 60 * 7 = 4200 l Since there's 15 ppm CO, multiply the volume breathed by 15x10^-6, getting 4200 * 15x10^-6 = 0.063 l Now, multiply the 0.063 l of CO breathed by its density of 1.2 g/l 0.063 * 1.2 g/l = 0.0756 g Convert from grams to milligrams by multiplying by 1000 0.0756 * 1000 = 75.6 mg