1. What is a conservation principle? Why is it useful in chemistry?
2. Which of the following properties of reactants and products are
always conserved during a chemical reaction?
(a) colour ; (b) temperature ; (c) number of atoms ; (d) number
of bonds ;
(e) kinds of bonds: ionic, covalent etc. ; (f) energy ; (g) molecular
(h) mass ; (i) electrical conductivity ; (j) dipole moment ; (k)
number ; (l) total of mass and energy
3. In what way does a zero net change in oxidation number for all
participants in a reaction represent conservation of electrons?
4. What is the hidden assumption when we use conservation of mass
as being equivalent to the conservation of the number of each kind
5. What is the difference between weight and mass? Which would change
and which would stay the same on going from the Earth to the moon?
Would the one that changes be greater, or less, on the moon?
6. How can we use the weighing operation to tell how many atoms
are present in a sample of material, although the direct counting
of atoms is impossible?