Composition (Grade 10 NSC Matric Physical Sciences): Flashcards

$n = \frac{m}{M}$ where $n$=moles, $m$=mass(g), $M$=molar mass

$\frac{\text{atomic mass}}{\text{molecular mass}} \times 100\%$

Simplest whole number ratio of atoms in a compound

Actual number of atoms in a compound

Molecular formula is a whole number multiple of empirical formula

% by mass, formula from %, combustion analysis, waters of cryst.

Water molecules trapped within crystal structure of compounds

Convert percentages to masses (assume 100g sample)

Divide each by the smallest number of moles

Percentages should add up to 100%