C5 Chemical changes Flashcards
acid
when dissolved in water, its solution has a pH value less than 7. Acids are proton (H+ ion) donors
alkali
its solution has a pH value more than 7
base
the oxide, hydroxide, or carbonate of a metal that will react with an acid, forming a salt as one of the products. (If a base dissolves in water it is called an alkali). Bases are proton (H+ ion) acceptors
displacement reaction
a reaction in which a more reactive element takes the place of a less reactive element in one of its compounds or in solution
electrolysis
the breakdown of a substance containing ions by electricity
equilibrium
the point in a reversible reaction at which the forward and backward rates of reaction are the same. Therefore, the amounts of substances present in the reacting mixture remain constant
half equation
an equation that describes reduction (gain of electrons) or oxidation (loss of electrons)
ionic equation
an equation that shows only those ions or atoms that change in a chemical reaction
metal ore
a rock that contains enough of a metal or metal compound that it is worth extracting the metal
neutral
a solution with a pH value of 7 which is neither acidic nor alkaline. Alternatively, something that carries no overall electrical charge
neutralisation
the chemical reaction of an acid with a base in which a salt and water are formed. If the base is a carbonate or hydrogen carbonate, carbon dioxide is also produced in the reaction
ore
rock which contains enough metal to make it economically worthwhile to extract the metal
oxidation/oxidised
a reaction where oxygen is added to a substance / or when electrons are lost from a substance
pH / pH scale
a number which shows how strongly acidic or alkaline a solution is
reactivity series
a list of elements in order of their reactivity
