- Messages
- 124
- Reaction score
- 49
- Points
- 38
15 Use of the Data Booklet is relevant to this question.
The combustion of fossil fuels is a major source of increasing atmospheric carbon dioxide, with a
consequential rise in global warming. Another significant contribution to carbon dioxide levels
comes from the thermal decomposition of limestone, in the manufacture of cement and of lime for
agricultural purposes.
Cement works roast 1000 million tonnes of limestone per year and a further 200 million tonnes is
roasted in kilns to make lime.
What is the total annual mass output of carbon dioxide (in million tonnes) from these two
processes?
A 440 B 527 C 660 D 880
You see the total amount of limestone roasted is 1200 (1000+200)
Now we make the equation
CaCO3 => CaO + CO2
We find the moles of limestone = 1200/(40.1+12+ 16 x 3) = 11.98
Since the mole ratio of CaCO3:C02 is 1:1, we find the mass, we multiply by the mr of co2 which is 44. 11.9 x 44 = 527.47. Ans B