Amount of substance Flashcards
Avogadro’s constant
6.02 x 10^23
define molar mass
the mass (in g) of 1 mol of atoms of an element
- it’s equal to its relative atomic mass
define empirical formula
the simplest whole number ratio of atoms of each element present in a compound
define molecular formula
the number and type of atoms of each element in a molecule
define anhydrous
Not containing water molecules
define hydrated
Containing water molecules
define water of crystallisation
Water molecules attached to the crystal
moles equation
n=m/Mr
conc equation
n = cv
to convert from cm3 to dm3
divide by 1000
what are titrations used for
to determine unknown concentrations
units of conc
moldm-3 or gdm-3
ideal gas equation
- pV = nRT
- p - pressure (Pa)
- V - volume (m3)
- T - temperature (K)
- n - moles
- R - gas constant (8.314 JK-1mol-1
at RTP, 1 mole of gas molecules has a volume of
24dm3
what’s room temp and pressure (RTP)
- 20C
- 100 kPa
- 1 atm
equation for molar gas volume, Vm (ONLY WORKS AT RTP)
n = v/ 24dm3
define percentage yield
a measure of the % of reactants that have been converted into the desired product
define atom economy
a measure of the proportion of atoms from the reactants that form the desired products
equation for percentage yield
(actual no of moles of desired products)/ (theoretical no of mol of desired products) x 100
equation for atom economy
(Mr of desired product)/ (sum of reactant Mrs) x 100
- MULTIPLIERS INCLUDED IN CALCULATION
what are the ethical, environmental and economic benefits of high atom economy?
fewer raw materials are needed so it is more sustainable, chemical waste is minimised, more efficient, and less money is spent on separation processes
what’s a gas syringe and what can it be used for
volumes of gas, either given off by or delivered to experiments
- can be used to find the Mr of a volatile liquid or of an unknown metal
conversion from C to K
+273
conversion from dm3 to m3
divide by 1000 (x10^-3)
