Balance the following equation and use the table of enthalpies of formation at 2
ID: 1088180 • Letter: B
Question
Balance the following equation and use the table of enthalpies of formation at 25.0'C (see page 1) to answer the following questions GHz(g) +Orlg) _.cods) + _Molg) 12. What is the change in enthalpy for the combustion of acetylene gas? 13. How much energy is produced per gram of acetylene use? 14. How much energy is released per gram of carbon dioxide produced? Balance the following equation and use the table of enthalpies of formation at 25.0 C (see page 1) to answer the following questions. 15. What is the change in enthalpy for the combustion of hydrogen gas? 16. How much ènergy is produced per gram of hydrogen use?Explanation / Answer
2C2H2(g) + 5O2(g) ----> 4CO2(g) + 2H2O(g)
DHrxn = (4*co2+2*H2O)-(2*C2H2+5*O2)
= (4*-393.51+2*-241.8) - (2*226.7+5*0)
= -2511.04 kj
13. 2*26 g = -2511.04 kj
1 g of C2H2 = -2511.04*1/52 = -48.3 kj/g
14. 4*44 g = -2511.04 kj
1 g of CO2 = -2511.04/176 = -14.267 Kj/g
2H2(g) + O2(g) ---> 2H2O(g)
DHrxn = (-241.8*2)-(2*0+1*0)
= -483.6 kj
15. DHcomb = -483.6 kj
16. 2*2 g H2 = -483.6 kj
1 g H2 = -483.6*1/4 = -120.9 kj