Answer to Question 1
We know that burning is the combining of a compound with oxygen to produce
water and carbon dioxide. The burning of these two compounds in oxygen results in
differing amounts of CO2 and H2O.
Balancing the chemical equations, we may write
CH4 + X O2 -> Y CO2 + Z H2O,
where X, Y, and Z represent numbers that we will determine. We see that there is only one
carbon on the left, so there must be just one carbon on the right, meaning that Y = 1 . There
are four hydrogen atoms on the left, which is the same as two hydrogen molecules, so there
must be four atoms or two molecules' worth of hydrogen on the right, which means that Z
= 2 . There are two oxygen atoms (one oxygen molecule) associated with the carbon on the
right, and another two oxygen atoms (one oxygen molecule) associated with the water on
the right, so there must have been two oxygens on the left, meaning that X = 2 . So
CH4 + 2O2 -> CO2 + 2H2O
and we use the same method to write
5CH0.8 + 6O2 -> 5CO2 + 2H2O.
It is clear that there is a greater ratio of CO2 to water in the exhaust from burning CH0.8.
Answer to Question 2
As scientists, we should not have favorite models. There are models that have
not been shown to be incorrect and that we accept as a consequence, but we must be
prepared to throw it away if it can be shown to be incorrect.
It is possible that an experiment is set up incorrectly, or that it is set up correctly but is
misinterpreted. So scientists are not overly hasty in throwing models away. For this reason,
scientific experiments are described in enough detail to allow others to repeat them and are
repeated, to be as certain of their meaning as possible.
If, after such careful checking, the model is still found to be an incorrect description, it must
be discarded.
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