quantitive chemistry Flashcards
how to calculate percentage purity
pure/impure × 100
how to find percentage of an element in compound by mass
mass of element/molecular mass × 100
what is molecular mass?
the mass number of an element
What does Ar mean?
relative atomic mass
how to find Ar?
The mass number should be the proton number
Mr meaning
Relative molecular mass
how to find Mr
add up the Ar of the elements in the compound
eg. Mr of CO₂ = Carbon Ar = 12 + Oxygen Ar × 2 = 32
32+12 = 44 so Mr = 44
what is a mole?
a unit of measurement that connects different data measurements
how to find number of moles?
mass/Mr
what does it mean if there are more moles?
there is more mass
what is Avogadro’s constant?
I mole of any substance contains 6.02 × 10²³ particles
how to calculate total number of particles?
number of moles × Avogadro’s constant
what happens if two substances react in a 1:1 ratio?
their moles will be the same
how to calculate percentage yield?
actual/theoretical (in moles) × 100
how to calculate volume of gas/liquid using moles/
volume = number of moles × 2.4 × 10⁴cm
