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'Bucky Burner' printed from https://nrich.maths.org/
This question will require you to
engage in many different aspects of quantitative chemistry. Some
parts are related to previous parts, but others are not: you will
have to use your judgement in each case.
$1$kg of graphite is completely combusted. How much energy is
produced?
$1$kg of graphite is placed in an oxygen tank and completely
combusted, as is $1$kg of carbon-60. Which results in the largest
change in the total volume of gas present?
$1$kg of Buckminsterfullerine (carbon-60) is then burned and the
energy produced measured. Will it be more or less than that
produced by burning the graphite?
A $1$ carat diamond weighs $200$mg and the density of pure diamond
is $3.52$ g cm$^{-3}$. How big is a 1 carat diamond? Estimate the
number of C - C bonds contained in such a diamond. How accurate do
you think that your estimate is? What monetary value would you
place on each C - C bond in a flawless example of such a $1$ carat
diamond?
If this diamond were completely combusted, what volume of carbon
dioxide at standard pressure would be produced, once it had cooled
to room temperature? What volume of oxygen (measured at standard
pressure and temperature) would the reaction use up?
CHEMICAL DATA
The average bond enthalpy at room temperature of a C - C bond
is $+348$ kJ mol$^{-1}$
The reaction C(graphite) + O$_2\longrightarrow$ CO$_2$ has an
enthalpy change of $\Delta H=-393.5$ kJ mol$^{-1}$.
Average bond energies, kcal/mol
C-H 98; O-H 110; C-C 80; C-O 78; H-H 103; C-N 6;5 O=O 116 (2 x 58);
C=O 187* (2 x 93.5); C=C 145 (2 x 72.5); (* as found in CO2)
(NB 1 kJ/mol is equal to 0.239 kcal/mol. )