NY Regents Chemistry Exam June 2022
A 3% hydrogen peroxide solution, H2O2(aq), is commonly used as a disinfectant. Hydrogen peroxide, H2O2, decomposes as represented by the balanced equation below. 2H2O2 → 2H2O + O2 + heat
74. State evidence, from the equation, that the reaction is exothermic. 
Explanation: An exothermic reaction is the one that releases heat. For an exothermic reaction, we would see heat on the product side of the equation.
Answer: Heat is on the product side.
75. Explain, in terms of substances, why the reaction is a decomposition reaction. 
Explanation: In a decomposition reaction one substance breaks down into multiple substances.
Answer: One substance reacts to become two different substances.
76. State how increasing the temperature of the H2O2 affects the rate of the reaction. 
Explanation: Increasing the temperature of the reaction should increase the rate of the reaction.
77. On the potential energy diagram in your answer booklet, draw a double-headed arrow (↕) to indicate the interval that represents the heat of reaction. 
Explanation: The heat of reaction is the difference in energy between reactants and products.