Chemistry A Level Edexcel 267 Correctly Answered Questions Latest Update

Square Planar bond angle {Ans: 90}Tetrahedral bond angle {Ans: 109.5}Metallic Bonding {Ans: the strong electrostatic attraction between metal ions and the 'sea' of delocalised electrons}Why is 50% sulfuric acid used in the synthesis of bromoalkanes? {Ans: To prevent the formation of Br2}Enthalpy of Atomisation {Ans: Enthalpy change when 1 mole of gaseous atoms are produced from an element in its standard state}Allotropes {Ans: different forms of the same element in the same physical state}Halogenoalkanes + ammonia {Ans: Substitution reaction that forms aminoalkanes and ammonium salts; must use excess ammonia in a closed, heated container}4 Stages of a mass spectrometer {Ans: Ionisation. acceleration, deflection, detection}Vibration types (infrared spectroscopy) {Ans: symmetric stretch, asymmetric stretch, bending}Catalyst {Ans: a substance that provides an alternative reaction route of lower activation energy and hence speeds up the reaction. It is chemically unchanged at the end of the process so can be reused}How many electrons can the f orbital hold? {Ans: 14}Catalytic Converter Catalyst {Ans: Honeycomb of ceramic material coated with thin layer of platinum, palladium or rhodium}Examples of weak acids {Ans: ethanoic, citric}relative atomic mass {Ans: the average mass of an atom