Chemistry - Thermochemistry Question with Solution | TestHub
A quantity of 0.3 g of carbon was converted into CO2 producing 2400 cal of heat. When carbon was converted to CO, 1400 cal of heat were produced. What will be the heat produced when 0.7 g of CO is converted to CO2?
Options:
Answer:
Solution:
For the combustion of 0.3 g of carbon (C) to carbon dioxide (CO₂), the heat released is 2400 cal.
For the combustion of 0.3 g of carbon (C) to carbon monoxide (CO), the heat released is 1400 cal.
The difference in heat, 2400 - 1400 = 1000 cal, corresponds to the heat released when the carbon monoxide (CO) formed from 0.3 g of carbon is further converted to carbon dioxide (CO₂).
First, calculate the moles of CO produced from 0.3 g of C:
Moles of C = 0.3 g/(12 g/mol) = 0.025 mol
Since 1 mole of C produces 1 mole of CO, the moles of CO formed are 0.025 mol.
The heat released per mole for the conversion of CO to CO₂ is:
1000 cal/0.025 mol = 40000 cal/mol
Now, consider 0.7 g of CO.
Moles of CO = 0.7 g/(28 g/mol) = 0.025 mol
The heat released when 0.7 g of CO (0.025 mol) is converted to CO₂ is:
0.025 mol × 40000 cal/mol = 1000 cal
This corresponds to option (d).
