moles 1 and organics Flashcards
What is meant by the term “relative atomic mass”?
The average mass of all isotopes of an element, taking into account their abundance
RFM is?
relative formula mass = use periodic table and add up mass numbers to find rfm for compound
Equation linking mass rfm and moles?
mass = rfm x moles
To find the percentage mass of an element in a compound do
Element’s mass in compound/RFM of compound x 100
what is water crystallisation
when salt forms crystals a particular amount of water gets trapped in the crystals = trapped water is water crystallisation
equation for percentage yield
PERCENTAGE YIELD = ACTUAL YIELD/THEORETICAL YIELD X 100
What might the reasons be for not making the theoretical yield (100% yield)?
Incomplete reaction
Loss of products
Impure reactant
Why do we deliberately put in too much of one reactant
the aim of this is to make sure that all of the other reactant(s) gets used up.
define molecular formula
only shows how many carbon+hydrogen atoms there are
define empirical formula
shows simplest whole number ratio of carbon to hydrogen
define displayed formula
diagram showing positions of every atom + bond
define functional group
The C with all the dashes around it - determined all the chemical properties of a compound
define structural formula
shows structure of molecule in on line read from left to right e.g CH3, CH2, CH2, CH3
define homologous series
a family of molecules with similar chemical reactions and same general formula
define hydrocabon
compound made of hydrogen and carbon only
