1.
The diagram shows part of the mass spectrum for chloroethane, C2H5Cl.
What ions are responsible for the peaks at m/e 66 and 64, and 29 and 28?
66 &/or 64: C2H5CI+ (1) 2 isotopes of chlorine (1); NOT
29 & 28:
C2H5+ (1)
13C
(abundance too low)
C2H4+ (1)
penalise missing charges ONCE and ONCE ONLY
(4)
From the position of radium in the periodic Table, predict the following:
(a)
the formula of radium carbonate;
(b)
the equation of the thermal decomposition of solid radium carbonate;
m
2.
(c)
.co
RaCO3(s) → RaO(s) + CO2(g) (2)
balanced equation (1) state symbols (only if correct species) (1)
how the decomposition temperature required in (d)(ii) would compare with tat required
for magnesium carbonate.
(Total 4 marks)
ww
w.
ch
em
ac
ti
ve
(temperature) higher (for Ra) (1)
NT Exampro
1