Question

Every year in the US, we get 20.8 EJ of energy from coal. How many kg of carbon dioxide is produced from the combustion of that coal? (give your answer to the tenth place--one decimal point--in proper scientific notation)

(assume that it is bituminous or anthracite coal)

________ x10_______kg

Answer 1

Energy = 20.8 EJ = 20.1 x 10^ 18 Joules

we need table which gives amount of CO2 per energy released

since its not mentioned here we use web values

anthracite gives 228.6 pounds CO2 per million BTU units

now million BTU = 10^6 BTU = 10^6 x 1055.06 J = 1.055 x 10^ 9 J

CO2 pounds = 228.6 , CO2 in kg = 228.6 x 0.453592 = 103.69 kg

hence per 1.055 x 10^ 9 J we get 103.69 kg CO2

per 20.8 x 10^ 18 Joules we get

= 103.69 x ( 20.8x10^ 18) / ( 1.055x10^9) = 2.0 x 10^12 kg