CHEM SCH4U Understanding Energy and Reaction Rates Questions And Correct Answers |100% Verified |Guaranteed Success | update

1. Which of the following reactions is endothermic? a. b. c. A + B → AB ΔH = - 275 kJ/mol CD + 300 kJ/mol → C + D d. A dissolution reaction in a calorimeter where the initial temperature is 13°C and the final temperature is 22°C. 2. Which equation would correctly calculate the enthalpy for the reaction: 2H2 + O2(g) → 2H2O(g)? 3. Which of the following best describes the changes in reaction rate for the reactants as a reaction progresses? a. Reaction rate is highest at the beginning and decreases over time b. The reaction rate is slow at first, then increases c. The reaction rate remains relatively constant for the duration of the reaction d. The reaction rate is highest at the beginning and end of a reaction 4. Which of these would be the closest to an isolated system? a. A well-insulated steel thermos b. Earth c. A sealed plastic container d. All of the above are examples 5. A chemical engineer is performing a test to see if a proposed catalyst for an industrial chemical reaction is working effectively. Which of the following would be positive evidence that it’s working? a. The enthalpy of the reaction increases b. Less heat is required to get the reaction started c. The reaction creates new products d. The enthalpy of the reaction decreases 6. Using bond enthalpies (from your reference page), how much energy is required to create one mole of formaldehyde, CH2O? a. 1184 kJ b. 876 kJ c. 1898 kJ d. 1625 kJ 7. Which of the following could be a rate law for a fourth order reaction? a.