BRAINCAKEPredicting and identifying reactions
Revision notes for Predicting and identifying reactions in OCR Chemistry A (J248). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- Properties of Groups 1, 7 and 0The alkali metals in Group 1 (lithium, sodium and potassium) are soft enough to cut with a knife and are shiny when freshly cut.
- Group properties and outer shell electronsThe properties of a group depend on the electrons in the outer shell.
- Transition metals and their compoundsThe transition metals sit in the block between Group 2 and Group 3 of the Periodic Table.
- Predicting reactions from the Periodic TableAn element's position in the Periodic Table lets us predict how it reacts.
- Reactivity of metals with water and acidsWhen a metal reacts, its atoms lose electrons to form positive ions.
- Deducing an order of reactivityA displacement reaction happens when a more reactive metal displaces a less reactive metal from a solution of its salt.
- Tests for gasesFour gases can be identified with simple tests.
- Tests for aqueous cations and anionsMetal ions in solution can be identified by adding a few drops of sodium hydroxide solution.
- Carrying out a flame testA flame test identifies metal ions by the colour they give to a flame.
- Identifying species from test resultsAn unknown solution can be identified by combining the tests for positive and negative ions.
- Interpreting flame testsEach metal ion gives a flame colour that can be used to name it.
- Advantages of instrumental methods of analysisChemical tests such as precipitates and flame tests rely on a person to judge a colour by eye, and they need a fairly large amount of sample.
- Interpreting instrumental resultsAn instrumental method gives its result as a chart or a table of numbers.