Unit Conversion Example Problem - Metric to English Conversion

Worked Chemistry Problems

Grams per liter can be converted into pounds per cubic foot.
John Kuczala / Getty Images

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