Chemical Energetics Flashcards
Define the term exothermic reaction.
An exothermic reaction is a reaction that gives out heat energy
Define the term endothermic reaction
An endothermic reaction is a reaction that takes in heat energy
Name the piece of equipment used to measure temperature changes.
The piece of equipment used to measure temperature changes is a thermometer.
Are the reactants higher or lower in an exothermic reaction?
Higher
Are the reactants higher or lower in an endothermic reaction?
Lower
Define the tern enthalpy change (ΔH)
The overall energy change in a chemical reaction
Does an exothermic reaction have a positive or negative enthalpy change?
An exothermic reaction has a negative enthalpy change.
Explain the term activation energy
Activation energy is the initial increase in energy, from the reactants to the peak of the curve, required to start the reaction.
What is the symbol for activation energy?
Ea
How does a reaction profile show that a reaction is endothermic?
An energy level diagram show that a reaction is endothermic because the the energy of the products is higher than the energy of the reactants
What does an downwards arrow on an energy level diagram indicate?
A downwards arrow on an energy level diagram indicates an exothermic reaction.
What does an upwards arrow on an energy level diagram indicate?
An upwards arrow on an energy level diagram indicates an endothermic reaction.
State the equation used to calculate energy change using bond energies
energy change = energy taken in - energy given out
Give the unit of energy change.
kJ mol-1