This worked chemistry example problem demonstrates how to convert from metric units to English units.
Problem
Analysis of an air sample reveals that it contains 3.5 x 10-6 g/l of carbon monoxide. Express the concentration of carbon monoxide in lb/ft3.
Solution
Two conversions are required, one from grams to pounds using this conversion:
1 lb = 453.6 g
and the other conversion, from liters to cubic feet, using this conversion:
1 ft3 = 28.32 l
The conversion may be set up in this fashion:
3.5 x 10-6 g/l x 1 lb / 453.6 g x 28.32 l / 1 ft3 = 0.22 x 10-6 lb/ft3
Answer
3.5 x 10-6 g/l of carbon monoxide is equal to 0.22 x 10-6 lb/ft3
or, in scientific notation (standard exponential notation):
3.5 x 10-6 g/l of carbon monoxide is equal to 2.2 x 10-7 lb/ft3

