Flashcards in C5 - energy changes Deck (17)
Define an exothermic reaction
Energy is given out to the surroundings because more energy was given out by making bonds than was taken in for breaking bonds
Does an exothermic reaction get warmer or colder?
define an endothermic reaction
Energy is taken in from the surroundings because more energy was taken in for breaking bonds than was given out by breaking bonds
does an endothermic reaction get warmer or colder?
Give two examples of an exothermic reaction
combustion, neutralization reactions
Give two examples of endothermic reactions
the reaction between citric acid and sodium hydrogencarbonate, thermal decomposition (photosynthesis also counts but it isn't in the book)
give two uses of exothermic reactions
some hand warmers and self-heating cans
give a use of endothermic reactions
some sports injury packs
what are reaction profiles?
diagrams that show the relative energies of the reactants and products in a reaction, and how the energy changes over the course of the reaction
If the reactants are higher than the products in a reaction profile, is the reaction exothermic or endothermic?
if the reactants are lower than the products in a reaction profile, is the reaction exothermic or endothermic?
what is the name of the initial rise of energy in a reaction profile?
what is activation energy?
the minimum amount of energy the reactants need to collide with each other and react. The greater the activation energy, the more energy needed to start the reaction.
what does the overall difference in height of a reaction profile represent?
the overall energy change during the reaction
Does breaking bonds require energy or release energy? Is it exothermic or endothermic?
It requires energy - it is endothermic
does forming bonds require energy or release energy? is it exothermic or endothermic?
It releases energy - it is exothermic