Chapter 3 Flashcards
Avogadros constant
6.02x10^23 mol^-1
no of particles=
moles x avogadros constant
mass, mr, moles
moles= mass/mr
molar mass=
relative atomic mass for a substance
difference between Ar and Mr
mr has units, ar doesn’t
empirical formula
simplest whole number ratio of atoms of each element in a compound
molecular formula
actual number of atoms of each element in a compound
non metal+metal
ionic
non metal+ non metal
covalent
ethane empirical and molecular formula
empirical= CH3
molecular=C2H6
Hydrated salt
ionic solid containing water molecules
anhydrous
ionic solid with no water molecules
water of crystallisation
water molecules in an ionic solid
experimental errors of hydrated salt practical + prevention
- not all water removed= smaller ratio
-mass reading error=use more accurate balance
-further decomposition(CuSO4 to Copper(ii)oxide)= be careful when heating
percentage uncertainty/error
uncertainty/quantity measured x 100
percentage uncertainty of CHANGE
2 x uncertainty/change measured x 100
reduce percentage error
higher resolution equipment, more DP
increase quantity of what is measured
efflorescent
loses water of crystallisation to atmosphere
deliquescent
absorbs moisture from the air
conc, vol, mol
mol = conc x vol
at the same temperature and pressure, equal volumes of different gases
contain the same number of molecules
room temperature
20 degrees celsius
room pressure
101kPa/ 101,000 Pa
volume, molar gas, moles
moles= volume/molar gas(Vm)
