CHEMISTRY MISTAKES

test for calcium

• flame test

• orange-red flame

test for ammonium ion

• add SODIUM HYDROXIDE and warm

• pungent gas is released

test for ammonia gas

• turns damp red litmus paper blue

test for chlorine ions

• add DILUTE NITRIC ACID

• then add SILVER NITRATE SOLUTION

• a white precipitate is formed

test for lithium ions

• flame test

• red flame

two characteristics of a reaction at dynamic equilibrium

• forward and backward reaction occurs at the same rate

• concentration of reactants and products remain constant

ionic bond

strong forces of attraction between oppositely charged ions

test for cation

• add sodium hydroxide solution

• if blue precipitate forms = contains copper(ii) ions

• if green precipitate forms = contains iron(ii) ions

test for anion

• add silver nitrate solution

• if white precipitate = contains chloride ions

• if cream precipitate = contains bromide ions

how is diamond suitable for cutting tools?

how is graphite suitable for pencils?

why the student needs to clean the platinum wire (for a flame test)?

• remove any other substances

• so it will not mask the colour of the flame

test for sodium

• flame test

• yellow flame

test for sulfate ions

• add dilute hydrochloric acid

• add barium chloride solution

• white precipitate appears

reaction between ammonia and sulfuric acid

neutralisation

why does the mass of the contents decrease?

carbon dioxide gas is given off

explain the shape of the graph (marble chips)