All Flashcards
Describe the process of calculating ΔH.
ΔH = H(products) - H(reactants). Subtract the enthalpy of the reactants from the enthalpy of the products.
How do you determine activation energy (Ea) from an energy diagram?
Ea = (Energy of activated complex) - (Potential energy of reactants).
What is the effect of a negative ΔH on a reaction?
The reaction is exothermic, releasing heat to the surroundings.
What is the effect of a positive ΔH on a reaction?
The reaction is endothermic, absorbing heat from the surroundings.
What happens to the temperature of the surroundings during an exothermic phase change?
The temperature of the surroundings increases as heat is released.
What happens to the temperature of the surroundings during an endothermic phase change?
The temperature of the surroundings decreases as heat is absorbed.
What are the key differences between exothermic and endothermic reactions?
Exothermic: Releases heat, ΔH < 0, products have lower energy. Endothermic: Absorbs heat, ΔH > 0, products have higher energy.
How do energy diagrams differ for exothermic vs. endothermic reactions?
Exothermic: Downward slope from reactants to products. Endothermic: Upward slope from reactants to products.