energy changes Flashcards
(28 cards)
what is an exothermic reaction
the transfer of energy from molecules to the surroundings
do the surroundings get colder or hotter in exothermic reactions
hotter
what is an endothermic reaction
the transfer of energy from the surroundings to the molecule
do the surroundings get hotter or colder in endo thermic reactions
colder
what is activation energy
the minimum amount of energy the reactant particles need in order to collide with each other and react
what is bond energy
amount if energy needed to break one mole of a particular covalent bond
is bond formation endothermic or exothermic
exothermic
is bond breaking endothermic or exothermic
endothermic
if the reaction change is negative is it exothermic or endothermic
exothermic
if the reaction change is positive is it exothermic or endothermic
endothermic
does formation release or take in energy
release
does breaking release or take in energy
take in
how do you work out energy change
breaking - formation
how can we produce electricity
two different metals in an electrolyte
what is an electrolyte
a solution that can conduct electricity
why can a cell produce metal for an certain amount of time
solution runs out
the greater the difference between metals in a cell what does this mean
the greater the potential difference ( voltage)
what is a battery
two or more cells in a series that produce a greater voltage
what is a non rechargeable batteries
a battery that reaction that cannot be reversed
what is a rechargeable batteries
a batteries reactions that can be reversed by applying an electrical current
how do we reverse a batteries reaction
an electrical current
what type of batteries are non rechargeable
alkaline
3 factors that affect voltage
metal used-reactivity
type of electrolyte used
conditions e.g temperature
what’s the overall word reaction for fuel cells
hydrogen oxygen -> water
