amounts of substance Flashcards
(16 cards)
define amounts of substance
is a quantity used by Chemists to count the
number of particles in a substance. This has the unit of a mole (mol).
define one mole of a substance
the amount of substance that contains the same number of particles (atoms, ions or
molecules) as there are atoms in exactly 12g (i. e one
mole) of 12C.
define Avogadro’s constant
the number of chemical
particles (atoms or molecules) in one mole of a substance.
(6.02 x 1023 mol-1)
where did the mole come from
-how many atoms was in 12g of carbon-12
define molar mass
the mass of a substance that contains one
mole of that substance. (g mol-1)
what is stoichiometry
- the calculation of the quantities of chemical elements or
compounds involved in chemical reactions. - the branch of chemistry dealing with relationships of
combining elements, especially quantitatively.
what is atom economy
the mass of the product you want as a % of the mass of all
the products you make
how to calculate atom economy
Mr of desired product/ Mr of total products x100
why is atom economy important
-Resources are finite.
-We need to dispose of as little waste as possible for
environmental reasons.
- Costs of raw materials
how to calculate percentage uncertainty
uncertainty/ quantity measured x100
how to calculate 1 mole of a gas
volume/ 24
what does avogadros law say about volumes of gas
Equal Volumes of gases at constant temperature and pressure contain
equal numbers of molecules.
what does charles law say about volume and temperature
The volume of a fixed amount of gas, at a constant pressure is
proportional to the absolute temp
what does boyeles law say about volume and preassure
At constant temperature, the
volume of a fixed amount of
gas is reduced in proportion as
the pressure increases.
what is the ideal gas equation with units
pV=nRT
p=Pa
V=m^3
n=mol
R=8.314
T=K
when is ideal gas equation used
when conditions are not RTP
