chemical reactions core questions Flashcards
define reactants
substances that react together
define products
a substance made in a reaction
what are common signs of a chemical reaction
temperature change
colour change
change of state
emitting fumes
what is a displacement reaction
when a more reactive element takes the place in a compound of a less reactive element
what does the suffix ide mean
only that element present e.g. chloride or oxide
what is the reactivity series
list of chemicals (mainly metals) in order of reactivity
which metals do not react with acids
copper
silver
gold
platinum
as they are less reactive than hydrogen
what is thermal decomposition
breaking down a substance using heat
what is a combustion reaction
when a fuel reacts with oxygen (heat and light are produced
what is an endothermic reaction
when energy is taken in from the surroundings (normally results in temp going down)
what is an exothermic reaction
when energy is released into the surroundings (normally results in temp increasing)
what is a catalyst
a substance that speeds up a chemical reaction without being used up
what does biodegradable mean
something that decomposes(broken down) by bacteria
what is the general equation for complete combustion
fuel(e.g.propane) + oxygen
-> carbon dioxide + water
what are some examples of a physical change
change of state (melting, boiling, evaporating)
mixing
dissolving