3.1.2 Amount of substance

Question 1

What is meant by the term a mole of molecules?

Answer 1

Avogadro’s constant
6.022 x 10^23

Question 2

Give the meaning of the terms:
a) molecular formula
b) empirical formula

Answer 2

a) The number of atoms of each element in a compound

b) The simplest ratio of atoms of each element in a compound

Question 3

Define the terms relative atomic/molecular mass.

Answer 3

The weighted average mass of an atom of an element/molecule relative to the mass of carbon 12 (defined as exactly 12)

Question 4

For what reasons may the % yield be more/less than 100?

Answer 4

More: incomplete reaction, residue left behind
Less: product contains impurities