Energy From Reactions Flashcards
How can energy released when substances burn be measured
Calorimetry e.g. Hearing water in glass or metal container
How is energy normally measured in
Joules
How can amount of energy released or absorbed by chemical R in sol be calculated
Measured temp change of sol when reagents mixed in insulated container
Used for solids with water or neutralisation reactions
What are energy level diagrams used for
Show relative energies of reactants and products e.g. Activation and overall energy change
During a chemical reaction what 2 things must the energy be
Supplied to break bonds
Released when bonds form
What happens to energy released in exothermic
Energy released so new bonds have greater energy than needed to break
What happens to energy in endothermic reaction
Energy needed to break bonds is greater than energy released when forming
What do catalysts do in a reaction
Lower activation energy
How can hydrogen be used
As a fuel Or fuel cells to produce electricity to power vehicles
Why is hydrogen a good fuel environmentally
Reacts with oxygen when burnt to form water
