Formulas

Question 1

Relative atomic mass (Ar)

Answer 1

Sum of (isotope abundance x isotope mass number) / sum of abundance of all the isotopes

Question 2

Percentage mass of an element in a compound

Answer 2

Ar x number of atoms of that element / Mr of the compound

X 100

Question 3

Number of moles

Answer 3

Mass in g (of an element or compound) / Mr (of the element or compound)

Question 4

Concentration

Answer 4

Mass of solute / solvent

Question 5

Mass

Answer 5

Concentration x volume