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What is the heat of combustion per gram of butane?

5. The combustion of butane produces heat according to the equation
2C4H10(g) + 13O2(g)  8CO2(g) + 10H2O(l) H° = -5,314 kJ
What is the heat of combustion per gram of butane?
A.-32.5 kJ/g
B.-45.7 kJ/g
C.-91.5 kJ/g
D.-2,656 kJ/g
E.-15,440 kJ/g

6. The freezing of water is an example of an exothermic change.

7. Calcium oxide and water react in an exothermic reaction.
CaO(s) + H2O(l)  Ca(OH)2(s) H° = -64.8 kJ/mol
How much heat would be liberated when 7.15 g CaO(s) is dropped into a beaker containing 152 g H2O?
A.1.97 x 10-2 kJ
B.8.26 kJ
C.508 kJ
D.547 kJ
E.555 kJ

8. How much heat is absorbed in the complete reaction of 3.00 grams of SiO2 with excess carbon in the reaction below? H0 for the reaction is +624.6 kJ.

SiO2(g) + 3C(s)  SiC(s) + 2CO(g)
A.366 kJ
B.1.13  105 kJ
C.5.06 kJ
D.1.33  104 kJ
E.31.2 kJ

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5. The combustion of butane produces heat according to the equation
2C4H10(g) + 13O2(g)  8CO2(g) + 10H2O(l) H° = -5,314 kJ
What is the heat of combustion per gram of butane?
The heat given is per mol of butane. Molecular weight of butane is:
4*12+10=58 (g/mol)
So heat per g is -5,314/58 = -91.6 ...

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