chemical changes
the ph scale - measures of how acidic or alkane a solutions
low numbers are acidic
high numbers are alkali
0-14
indicators
change colour depending on the PH scale
universal indicator
chemical dyes
definitions
Ph is a concentrations of H+ ions
Bases - any substances with a Ph greater than 7
alkali - a base that dissolves in water to form a solution with a Ph greater than 7
acid - any substances that forms an aqueous solution with a PH less than 7
neutralisation reaction always make salt and water reacting an acid and bases
ionise completely
all the acids particles will dissocate
concentration
how much there is in a certain volume
neutralisation reactions
metal oxide + acid - salt + water
neutralisation steps - dilute acid in a beaker and gently heat it with a bunsen burner, then add insoulble base a little at a time to start with the base will disappear after a while some of the base will no longer disappear, this means we would have neutralised the acid, then filter the solution you will be left with dissolved soulble salt. then gently heat the salt in a water bath so some of water will evaporate off
metal hydroxide + acid - salt + water
acid + metal carbonate - salt + water + carbon dioxide
oxidation
2Mg + O2 - 2MgO
oxidisation the magnessium
the process of gaining oxygen
loss of electron
reduction
2MgO - O2 + 2Mg
reduced
loss of oxygen
gain of electrons
Metal + acid - salt + hydrogen
as we go down the the table the reaction will get less violent
Metal + water - metal hydroxide + hydrogen
as we go down the the table the reaction will get less violent