Bond breaking is an endothermic change and bond forming is an exothermic change. Bond energy is the amount of energy in kJ/mol needed to break one mole of the specified bor
H
H
H
H
H
H
H
C
.C
H
CI
H
0 0 0 0
HCI
H
H
H
H
H
H
Use the following bond energies to determine whether this reaction is exothermic or
endothermic. You must show your reasoning.
bond
bond energies in
KJ/mol
CCI
338
CH
412
CH
CI-CI
242
H-CI
431
348
I

7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation. 8. when a 2.5 mol of sugar (c12h22o11) are added to a certain amount of water the boiling point is raised by 1 celsius degree. if 2.5 mol of aluminum nitrate is added to the same amount of water, by how much will the boiling point be changed? show all calculations leading to your answer or use 3 – 4 sentences to explain your answer. 9. if 5.40 kcal of heat is added to 1.00 kg of water at 100⁰c, how much steam at 100⁰c is produced? show all calculations leading to an answer. 10. the freezing of water at 0⁰c can be represented as follows: h2o (l) ↔ h2o(s) the density of liquid water is 1.00 g/cm3. the density of ice is 0.92 g/cm3. in 3 – 4 sentences explain why applying pressure causes ice to melt.