preparing common salts
reacting acids and alkalis
an acid is a substance that has a ph level under 7
an alkali is a substance that has a ph level above 7
it is specifically a soluble base
bases are soapy in nature, making them slippery
hydrogen ions are acids
hydroxide ions are alkalis
strong acids dissociate completely, while weak acids dissociate partially
acids have a sour taste
e.g citrus fruit
ph scale ranges from 0-14
acid turns blue litmus paper red
the main acids in science are DNA and RNA
class notes
an acid is a substance that dissolves in water to produce hydrogen ions
an alkali is a substance that dissolves in water to produce hydroxide ions
a salt is the substance formed when an acid reacts with an alkali
this is called neutralisation
acid | alkali | |
hydrochloric acid (HCl) | sodium hydroxide (NaOH) | |
sulfuric acid (H2SO4) | potassium hydroxide (KOH) | |
nitric acid (HNO3) | calcium oxide (CaO) | |
ethanoic acid (H2COOH) | ammonia (NH3) | |
carbonic acid (H2CO3) | calcium hydroxide (Ca(OH)2) |
there are two types of salts
soluble
sodium salts
potassium salts
nitrates
insoluble
carbonates (excluding potassium and sodium carbonates)
silver chloride
lead sulfate
lead chloride
barium sulfate
soluble salts
acid + metal = salt + hydrogen
nitric acid + magnesium → magnesium nitrate + hydrogen
acid + metal carbonate = salt + carbon dioxide + water
hydrochloric acid + calcium carbonate → calcium chloride + carbon dioxide + water
acid + insoluble base = salt + water
sulfuric acid + copper(II) oxide → copper(II) sulfate + water
acid + alkali → salt + water
hydrochloric acid + sodium hydroxide → sodium chloride + water
insoluble salts
made by precipitation reaction
this involves two soluble salts
soluble salt + soluble salt → soluble salt + insoluble salt
lead (II) nitrate + sodium carbonate → sodium nitrate + lead(II) carbonate
silver chloride | AgCl | |
barium sulfate | BaSO4 | |
lead carbonate | PbCO3 | |
lead sulfate | PbSO4 |
state symbols
s - solid
l - liquid
g - gas
aq - aqueous - soluble in water