june 2020- paper 1

Question 1

relative atomic mass (2)

Answer 1

mean mass of an atom / 1/12 the mass of 1 atom of 12C

Question 2

why do molecules need to be ionised before they can be analysed in a TOF mass spectrometer? (2)

Answer 2

• ions can be accelerated

- generate a current when they hit the detector

Question 3

phosphorus (V) oxide

Answer 3

P4O10

Question 4

why are solutions containing [Al(H2O)6]3+ acidic? (3)

Answer 4

[Al(H2O)6]3+ >< (arrow thingy) [Al(H2O)5(OH)]2+ + H+
Al3+ high charge density
releases H+ as OH bond in water is weakened

Question 5

redox reaction between NaBr and H2SO4

Answer 5

2NaBr + 2H2SO4 > SO2 + 2H2O + Br2 + Na2SO4

Question 6

aqueous chlorine + sodium bromide

Answer 6

Cl2 + 2Br- > Br2 + 2Cl-

orange solution

Question 7

conventional representation of a glucose fuel cell

Answer 7

C|C6H12O6, H+ | CO2 || O2 │H+ ,H2O│Pt

Question 8

what must be done to maintain the emf of a glucose fuel cell?

Answer 8

continually add reactants