All Flashcards
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.
In a typical energy diagram, what does the y-axis represent?
Potential Energy (usually in kJ or J).
In a typical energy diagram, what does the x-axis represent?
Reaction Progress or Reaction Coordinate.
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).