Endo/exo Flashcards
Why is it important to know the amount of energy involved in a chemical reaction?
- To measure the energy values of fuels
- To calculate the energy requirements for industrial processes
- To work out the theoretical amount of energy to break bonds and the amount of energy released when bonds are made
- It helps to predict whether a reaction will take place
How are bonds broken and what happens when they are made?
Energy must be added to break bonds and energy is released when bonds are formed, so most chemical reactions involve an energy change
The ovarall change may result in energy being given out or taken in.
What is the difference between and exothermic reaction and an endothermic reaction?
At the end of the reaction, if energy has been given out ovarall, the reaction is exothermic, e.g water + anyhrous copper sulfate (CuSO4) + 5H2O → copper sulfate
At the end of the reaction, if energy has been taken in ovarall, the reaction is endothermic, e.g. thermal decomposition of copper sulfate (CuSO4.5H2O to anhydrous copper sulfate plus water
What is the rule about energy changes and reversible reactions?
It is always the case that a reaction that is endothermic in one direction is exothermic in the reverse direction.
What is energy changes usually measured in?
KJmol-1
