Question

The following quote is from the back of a bottle of Seventh Generation Natural Dish Liquid:

“If every household in the U.S. replaced just one bottle of 25 oz. petroleum-based dishwashing liquid with our 25 oz. vegetable-based product, we could save 81,000 barrels of oil, enough to heat and cool 4,600 U.S. homes for a year!”

According to the information in this statement…

a)   How many barrels of oil does a single U.S. household use each year for heating and cooling?

b)   Convert your answer in part a to liters, assuming one barrel is equal to 42 gallons.

c)    What is the underlying number of U.S. households assumed by the above statement? (Tip: You may assume that a bottle of petroleum-based dishwashing liquid is 10% petroleum by volume). Do you think this is a plausible estimate of the number of households in the U.S.? Please explain.

Answer 1

Ans (a) Barrels of Oil used by a Household each year for heating and cooling = Barrels of oil / No. of Us homes a year

= 81000 / 4600 = 17.6 barrels for one home (approx.) (on an average)

By a single household, (population = 324,310,011) Approximately. (2017 Census)

So, 81000 / 324,310,011 = 0.000249 barrels used by a single household in a year.

(b) 1 Barrel = 42 Gallons

0.000249*42 = 0.01045800033363 gallon

Now, converting gallon into liters,

1 gallon = 3.785411784 Liters

So, ( 0.01045800033363 gallon)* 3.785 = 0.03958 Liters

(c) We have assumed the no. of single household by the US Census 2017 data.

However, the no. of US household is mentioned in the statement as 4,600 .

We dont think so that this is a plausible estimate of the number of households in the US.