Definitions Flashcards
Anhydrous
No water molecules
Hydrated
Crystalline compound containing water molecules
Water of crystallisation
Water molecules bonded into a crystalline structure of a compound
Average bond enthalpy
Average enthalpy change that takes place when breaking by homolytic fission 1 mol of a given type of bond in the molecules of a gaseous species
Periodicity
Repeating trends in physical and chemical properties across a period
Trend of alkalinity
Increases down group
Indigestion treatment
Mg(OH)2 CaCO3 antacids
Neutralising acid soils
Ca(OH)2
Why carbonate test first
Baco3 (during sulfate) is white and insolube in water so you could get white precipitate if you carry sulfate test on carbonate
Neither sulf or halide produce bubbles, so carbonate has NO CHANCE OF WRONG ANSWER
can move on freely
Why halide test last
Agco3 and agso4 are both insolube in water so wiill form as precipitates
Why isnt combustion value accurate making it less exothermic
Incomplete combustion of methanol- CO proudced instead of co2
Heat loss to surrounding to beaker other than water
Evaporation of methanol from wick SO burner must be weighed as soon as flame estinguished. Or some methanol may have evaporated from wick. (Why soirit burners have cover)
How to minimise heat loss
Draught screens
O2 minimises heat loss erors and error from incomplete combustion
How to determine progress of chemical reaction
Monitoring remocal of reactant so decrease in conc
Monitoring formation of product so increase in conc
Economic importance of catalysts
Increases sustainability by lowering temperatures and reducing energy demand from the combustion of fossil fuels with resulting reduction in co2 emissions
Increase profitability
OUTWEIGHS costs of developing catalyytic process
How to determine rate of reaction
Monitoring vol of gas produced at regular time intervals usinf gas collection
Measuring loss of mass of reactants using balance
