Chemical changes

• Electrolysis must be used for sodium, calcium and magnesium.
• The reactivity series (most to least reactive) : potassium, sodium, magnesium, aluminium, zinc, iron, lead, hydrogen, copper, silver, gold, platinum.
• Limiting reaction is the reactant that runs out first.
• Carbon is used to reduce metal oxides and make pure metals.
• Ions can conduct electricity during electrolysis because they are free to move and they are charged
• Graphite is an excellent conductor if electricity, and it is relatively inert.
• Hydrogen gas is produced at the cathode in the electrolysis of brine.
• Are simple molecular, giant molecular or ionic compounds used in electrolysis?

  Ionic
• A metal should be extracted by carbon reduction when it is less reactive than carbon
• At the cathode, the least reactive element will be reduced.
• At the anode, hydroxide ion is oxidised, unless there's a halide present.
• Reduction with carbon only works for metals less reactive than carbon.
• Acids ionise or dissociate in water, releasing hydrogen ions
• Reactivity series: Please Stop Calling Me A Zebra, I Like Cute Silly Goofy Penguins
• Reactivity series: Potassium, sodium, lithium, calcium, magnesium, carbon, zinc, iron, hydrogen, copper, gold
• Acids react with some metals to produce salts and hydrogen
• A redox reaction is reaction where both oxidation and reduction occur
• A solution with pH 7 is neutral
• A strong acid is completely ionised in aqueous solutions
• Strong acids are hydrochloric, nitric and sulfuric acid.
• Weak acids only partially ionise in aqueous solutions.
• Weak acids are ethanol, citric and carbonic acids.
• As the pH decreases by one unit, the hydrogen ion concentration increases by a factor of 10.
• Litmus is red in acidic solutions and blue in alkaline solutions.
• Phenolphthalein is colourless in acidic solutions and pink in alkaline solutions
• Methyl orange is red in acidic solutions and yellow in alkaline solutions
• The dissociation of weak acids is a reversible reaction.
• Metal + acid = salt + hydrogen