C5 - Chemical changes Flashcards
Metal ores
A mineral or rock that contains a useful substance that can be mined for profit
Oxidised
A chemical reaction that involves the loss of an electron. Oxidation often involves the addition of oxygen and the loss of hydrogen ions.
Reduced
A type of chemical reaction. When a compound is reduced it loses oxygen, gains hydrogen or electrons
Reactivity series
A list of the elements in the order of their reactivity
Displacement reactions
A type of chemical reaction in which one element reacts with a compound of a second element and the result is the second element and a compound of the first element
Ionic equation
An equation which shows what happens to the ions in a reaction
Half equations
An equation involving either an oxidation or a reduction process. The electrons lost or gained in this process are shown in the equation.
Neutralisation
A chemical reaction in which an acid and a base interact with the formation of a salt.
Salts
A salt is a compound formed when some or all of the hydrogen in an acid is replaced by a metal
Acid
A sour substance which can attack metal, clothing or skin. The chemical opposite of an alkali. When dissolved in water, its solution has a pH number less than 7. Acids are proton (H+ ion) donors.
Alkalis
A soluble base with a pH greater than 7. Makes OH- ions in water.
Bases
The oxide, hydroxide or carbonate of a metal that will react with an acid, forming a salt as one of the products. Bases are proton acceptors.
Weak acids
An acid that does not split completely into its ions in solutions and produces a low concentration of hydrogen ions.
Strong acids
An acid that splits completely into ions in solution and produces a high concentration of hydrogen ions
Hydrogen ions
A hydrogen atom without its electron. Acids release hydrogen ions when they dissolve in water
Equilibrium
The point in a reversible reaction at which the forward and backwards rates of reaction are the same. Therefore, the amounts of substance present in the reaction mixture remain constant.
Strong alkalis
An alkali that splits completely into ions in solution and produces a high concentration of hydroxide ions
Weak alkalis
An alkali that does not split completely into its ions in solutions and produces a low concentration of hydroxide ions.
