8. Thermochemistry

Endothermic & Exothermic Reactions

Multiple Choice
Which of the following exchanges of energy has a positive sign for heat (relative to the system)?
Multiple Choice
If a cylinder equipped with a piston expands against an external pressure of 1.25 atm, increasing the volume of a cylinder by 0.500 L and releasing 25.0 J of heat, what is ΔE for the process?
Multiple Choice
A 0.1250-g sample of octane (C₈H₁₈) is burned in a bomb calorimeter with a heat capacity of 5.1 × 10² J/℃. The temperature inside the calorimeter increases by 11.8℃. What is the ΔE (in kJ/mol octane) for the combustion of octane?
Multiple Choice
Which of the following is the result of an exothermic process?
Open Question
The following reaction A --> B + C + heat is a(n) _____ reaction.
Open Question
The enthalpy of formation of water is -285.8 kJ/mol. What can be inferred from this statement?
Open Question
Which of the following processes is endothermic?
Open Question
Which one of the following is an endothermic process?
Open Question
Which of the reactions are exothermic?
Open Question
In which one of the following processes is the system endothermic?
Open Question
Which statement is true if the ΔH_rxn of a reaction is positive?
Open Question
2 Mg(s) + O₂(g) → 2 MgO(s) ΔH = −1204 kJ
Open Question
Identify which of the following is true for the reaction N₂(g) + 3 H₂(g) → 2 NH₃(g)
Open Question
Which has greater energy in an exothermic reaction, the reactants or the products?
Open Question
What would likely happen if you were to touch the flask in which an endothermic