Question 1
At 1.01
33 bar, the heat of sublimation of gallium is 277 kJ mol
-1 and the heat of vaporization is 271 kJ mol
-1. To the correct number of significant figures, how much heat is required to melt 5.50 mol of gallium at 1.01
33 bar?
◦ 6 kJ
◦ 33 kJ
◦ 244 kJ
◦ 274 kJ
Question 2
At constant pressure, the combustion of 20.0 g of C
2H
6(g) releases 1036 kJ of heat. What is Δ
H for the reaction given below?
2C
2H
6(
g) + 7O
2(
g) → 4CO
2(
g) + 6H
2O(
l)
◦ -173 kJ mol
-1◦ -779 kJ mol
-1◦ -1560 kJ mol
-1◦ -3115 kJ mol
-1