2.3 amount of substance

what is relative atomic mass?

Average mass of one atom of an element or compound relative to 1/12 the mass of one atom of carbon-12

what is relative molecular mass?

Average mass of an molecule of an element or compound relative to 1/12 the mass of one atom of carbon-12

what is relative formula mass?

Average mass of one formula unit of an element or compound relative to 1/12 the mass of one atom of carbon-12

how many molecules in one mole?

6.02 × 10^23

what is the unit for molar mass?

g mol^-1

what is the meaning of molecular formulae?

number of atoms in each element in a molecule

what is the meaning of empirical formulae?

simplest whole-number ratio of atoms of each element in a compound

what is analysis?

investigating the chemical composition of a substance

how are crystals described if water is apart of their crystalline structure?

hydrated

how are crystals described if water is not apart of their crystalline structure?

anhydrous

how to convert celsius to  kelvin?

+ 273

how to change kPa is Pa?

x 1000

how to change cm³ to m³?

x10^-6

how to change dm³ to m³?

x10^-3

what is the moles gas constant?

8.314

how many dm ³ to L?

1 dm³ is 1L

what is the units for concentration?

mol dm^-3

what is a standard solution?

A solution of known concentration

what is a molar gas volume?

volume per mole of gas molecules at a stated temperature and pressure

what does RTP mean?

room temperature and pressure

what is the normal room temperature and pressure?

20 degrees

101 kPa

at RTP how many dm³ is 1 mole of gas?

24

what is stoichiometry?

the ratio between substances in a balanced equation

how do u work out percentage yield?

actual yield/ theoretical yield x100

why is it difficult to achieve theoretical yield?

• reaction may not have gone to completion

• side reactions may have taken place alongside 

• product lost in the purification process

what is atom economy?

measure of how well atoms have been utilised

how do you work out atom economy?

sum of molar mass of desired products/ sum of molar masses of all products x100

what is the point of atom economy?

• to produce a large proportion of desired products and few unwanted waste products

• important for sustainability as makes the best use of natural resources