S1.4 Counting particles by mass: The mole

Avogadro’s constant

6.02 X 10²³

What is the relative atomic mass(Ar)

Weighted avg mass of one atom compared to 1/12th the mass of a carbon-12 atom

What is the difference between relative atomic mass and relative formula mass?

Atomic→one atom

Formula→compound or molecule

What is molar mass?

Same value as atomic mass

Measures mass present per 1 mole of specific element

How to convert particles to molar mass?

Avogadro’s particles→mole→molar mass

Formula triangle linking moles, particles and avogadro’s constant

What’s the difference between molecular and empirical formula?

Molecular- formula of actual molecule

Empirical- simplest ratio of the formula

%composition formula

[(Mr of specific element x n)/Mr of molecule] x 100

Molar concentration(molarity formula)

c=n/V

(V always in dm³: 1L→1000cm³→1dm³)

How do u represent molar concentration

Use square brackets, eg:

[CuCl2]= 0.36M

Formula for mass concentration

c=m(g)/V

What r the stp conditions?

Temp→0°C(273K)

Pressure→1 atm(100kPa)

Relationship between n and V

2 gases will have same amt of particles if they occupy same volume at stp

n1/n2=V1/V2

(Can use mole ratio)