June 2023 Paper 1 Flashcards
Suggest why the oxidation state of chromium is zero in Cr(PF3)6
PF3 is neutral and the complex is neutral
Give an equation for the reaction between sulfur dioxide and water
SO2 + H2O → H2SO3
Or
SO2 + H2O → 2H+ + SO3
2–
Explain why the enthalpy of hydration of fluoride ions is more negative than the
enthalpy of hydration of chloride ions.
fluoride ions/F– (ions) are smaller
-stronger attraction (of fluoride ion) to δ+ on H
e.g. why is the second ionisation energy greater than the first ionisation energy
the electron removed is closer to the nucleus
Describe how this solution is used to make 250 cm3 of the
0.100 mol dm–3 barium hydroxide solution.
-Transfers the solution to a volumetric/graduated flask
-Add washings using distilled water and make up to the
graduation mark/250 cm3
-Invert many times / shake to mix
Explain why the solution containing [Al(H2O)6]
3+ is acidic.
-Al
3+ has a high charge and small size
-Al
3+ weakens the O-H bond
An excess of aqueous ammonia is added to a solution containing [Al(H2O)6]
3+
Give an ionic equation for the reaction and state one observation.
-[Al(H2O)6]
3+ + 3 NH3 → Al(H2O)3(OH)3 + 3 NH4
+
White ppt or white solid
State why a fuel cell does not need to be electrically recharged.
Suggest one advantage of using methanol, rather than hydrogen, in a fuel cell for use
in cars.
-Methanol (is liquid so) can be stored easily or transported easily
How are the ions detected in a TOF mass spectrometer
-each ion gains an electron
How is the relative abundance of the ions in a TOF mass spectrometer determined
-current is proportional to abundance
Relative atomic mass
-the average mass of the atom of an element when measured on a scale where the mass of a C12 atom is exactly 12
Electrospray ionisation is used instead of electron impact for the ionisation of a protein
in a mass spectrometry experiment.
-the protein (ion) does not break up/fragment
what does adding potassium dichromate solution and warming test for?
primary and secondary alcohols
what does fehlings solution in a water bath test for?
tests for aldehydes
what does sodium hydrogen carbonate test for?
carboxylic acids
what does bromine water test for?
alkenes
