What is an ore ?
Rocks containing enough metal that it is economical to extract the metal.
State the reactivity series from most reactive to least reactive.
Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium
(carbon)
Zinc
Iron
Tin
Lead
(hydrogen)
Copper
Silver
Gold
Platinum
How do you test for hydrogen gas ?
squeaky pop when lit
Write the ionic equation and half equations: Mg + CuSO4 -> MgSO4 + Cu
ionic eq:
Mg + Cu(2+) –> Mg(2+) + Cu
half eqs:
Cu(2+) + 2e- –> Cu
Mg –> Mg(2+) + 2e-
General eq for a metal + acid.
metal + acid –> salt + hydrogen
What is a salt ?
A compound made when the hydrogen ions in an acid are partially or wholly replaced by metal or ammonia ions.
In a reaction between a metal and acid to form a salt, which of the two is oxidised and which is reduced ?
- metal oxidised
- acid reduced
General eq for acid + base.
acid + base –> salt + water
General eq. for acid + metal carbonate.
acid + metal carbonate –> salt + water + carbon dioxide gas
Describe how to obtain a pH curve.
- 20 cm^3 sodium hydroxide solution in beaker
- pH probe in beaker
- measure + record initial pH
- set up burette (rinse with distilled water then some hydrochloric acid) with hydrochloric acid in it
- add 5 cm^3 hydrochloric acid at a time whilst swirling beaker to mix
- measure + record pH between each addition
- observe when the pH suddenly jumps from alkaline to acidic; this is the pH curve
- plot on a graph
What is the relationship between H+ ion concentration and pH ?
If H+ ion conc. increases by 1 order of magnitude, pH unit decreases by 1.
