amount of substance

what is the avogadro constant?

• the number of atoms in 12g of carbon-12

what is the value of the avogadro constant?

6.022 x 10²³

what is a mole?

amount of substance that contains 6.022 x 10²³ particles

(unit of measurement for expressing the number of particles such as atoms, molecules or ions in a substance)

formula to calculate concentration

• conc = moles/vol(dm3)

• conc = mass (g)/vol (dm3)

formula to calculate moles

• moles = mass(g)/mr 

• moles = conc x volume

convert from cm3 to dm3

/1000

what is 1 mole of an atom equivalent to?

• the Ar in grams 

mass of 1 mole= Ar or Mr in grams

what is 1 mole of a molecule equivalent to?

the Mr in grams

what is 1 mole of Carbon?

12g

what is 1 mole of CO2?

44g

how to calculate the number of particles?

avogadros x no. of moles

(avagadro’s contant is the number of particles in 1 mole)

what is the ideal gas equation?

pV = nRT

what do all the letters in pV = nRT stand for (and units)?

• p = pressure (Pa)

• V = volume (m3)

• n = moles

• R = gas constant (8.31 JK-1mol-1)

• T = temperature (K)

how to convert from degrees celcius to kelvin?

+273.15

what is the empirical formula?

simplest whole number ratio of elements in a compound 

how to work out empirical formula

calculate the empirical formula of a compound with 23.3% Mg, 30.7% S & 46.0% O2

MgSO3

what is the molecular formula and how to find it

shows the actual number of atoms