Chemistry

Question 1

Formula for number of moles in a substance

Answer 1

N= Mass (g)/Mr (relative molecular mass)

Question 2

How is the Mr or Relative Molecular Mass of a substance found?

Answer 2

The atomic masses of all the atoms in a molecule are added.
E.g H20’s Mr is (2x1)+16
=18

Question 3

How is the Ar or Relative atomic mass found?

Answer 3

Adding up the weighted average of all isotopes of an atom. Found at the top of each element on the periodic table.