Energy changes - exo and endothermic reactions Flashcards
what is an exothermic reaction
a reaction which transfers energy / heat to it’s surroundings
how can we tell if a reaction is exothermic
the temperature of surroundings is hotter than when it started
how can we tell if a reaction is endothermic
there is a fall in temperature
examples of exothermic reactions
- combustion
- neutralisation
- many oxidation reactions
- respiration
these reactions give off energy
examples of endothermic reactions
- photosynthesis
- thermal decomposition
what are reaction profiles
diagrams that show the relative energies of the reactants and products in a reaction
how is an exothermic reaction shown in a reaction profile
products are at a lower energy than reactants
what is activation energy
the minimum amount of energy the reactants need to collide with each other and react
how is an endothermic reaction shown in a reaction profile
products are at a higher energy than reactants
how to find bond energies
energy required to break - energy required to make
examples of exothermic reactions we use in daily life
- hand warmers
- self heating cans
what requires energy
breaking a bond
what releases energy
making a bond
