As may 2019 Flashcards
Water bond angle
104.5
Atom economy
Product / total
Enthalpy change of reverse reaction
Opposite of Delta H
Electrophile
Electron pair acceptor
Percentage uncertainty
(Uncertainty / volume) x100
Explain the trend in boiling points of the halogens
Increases down the group
Increased London forces
More energy needed to overcome
You are supplied with a sample of ammonium bromide.
Describe simple tests that would identify the cation and anion present in ammonium bromide.
Include reagents, expected observations and relevant equations.
Test for Br– (anion)
Reagent AND observation
Silver nitrate/AgNO3 AND cream (precipitate)
Equation
Ag+ + Br– → AgBr
Test for NH4+ (cation)
Reagent and conditions –
(Heat with) NaOH
pH/indicator paper turns blue / purple / alkaline
Equation + –
NH4 +OH→NH3+H2O
Temperature and pressure used for standard enthalpy measurements
Temperature 298K
100kPa