Calculate CO2?

Question

How many pounds of CO2 will a car put in the atmosphere if it gets 35 MPG and will be driven 265,000 miles in its life time.

Answer 1

Assuming all the gas burns cleanly and ignoring the minor interactions that occur with elements in air:

265000 miles / 35 MPG = 7571 gallons

At 5.8 lb/gal, this is 43,900 lb of gas

Chemical formula for gas  averages about C7H16. Considering atomic weights of 12 for C and 1 for H,

gas = 7*12/(7*12+16) = 84% Carbon

Now, CO2 compared to C is:

(12+2*16)/12 = 3.67x heavier

So, 44,000 x 84% x 3.67 = 135,000 lb or 67 US tons.