7. The combustion of one mole of propane releases 2040 kJ of energy. How much energy is released by the combustion of one kilogram of propane? (Hint: First compute the mass in grams of one mole of...

*Solve the following problems and show solutions.

Extracted text: 7. The combustion of one mole of propane releases 2040 kJ of energy. How much energy is released by the combustion of one kilogram of propane? (Hint: First compute the mass in grams of one mole of propane.) 8. A large garage-door spring has a spring constant of 500 N/m. How much force must you exert to stretch this spring by 5 cm?