Amount of Substance
No description yet. This curated deck is ready for daily study.
Card preview (24)
Valency
number of bonds which that atom can form in a compound
relative atomic mass
average mass of an atom of an element on a scale where an atom of carbon-12 is exactly 12
relative molecular mass
average mass of a molecule of an element or compound on a scale where an atom of carbon-12 is exactly 12
relative formula mass
average mass of a formula unit on a scale where an atom of carbon-12 is exactly 12
empirical formula
the simpliest ratio of atoms of each element in a compound
molecular formula
actual number of atoms of each element in a molecule
reading
value found from a single judgement when using a piece of equipment
measurement
value found from the difference between the judgements of the two readings
atom economy
measure of what proportion of the products of a reaction are the desired product and how much waste
concentration
how much solute is dissolved in a known volume of solution
reading uncertainty
+/- 1/2 of the smallest division on the equipment
measurement uncertainty
+/- 1 of the smallest division on the equipment
reasons for a low yield
chemicals lost during transfer between containers reaction may be reversible other products formed in side reactions
volume of gas depends on
temperature pressure number of moles
ideal gases properties
no forces of attraction between particles size of particles is negligible
PV equation
PV = nRT
cm3 –> dm3
x10-3
dm3 –> m3
x10-3
mol dm-3 –> g dm3
x Mr
number of particles
No of particles = moles of substance (in mol) X Avogadro’s constant
solution
mixture formed when a solute dissolves in a solvent
Avogadro constant
The total number of particles in a mole of substance. Also called the Avogadro number. It is numerically equal to 6.022 × 10^23
Mole
A quantity of a substance that contains the Avogadro number (6.022 × 1023) of particles
Stoichiometry
Describes the simple whole number ratios in which chemical species react.