Other slides in this set

Slide 2

Preview of page 2

Here's a taster:

There is something you need to know:
Ar = relative atomic mass
Mr = relative molecular mass/relative formula mass
Basically all atoms are relative (compared) to Carbon.
The relative atomic mass will be given in the question, you don't need to remember
this.
For a compound:
To get the relative molecular mass you need to add the relative atomic
mass of all the elements.
E.g. Work out the molecular mass of Cu(OH)2 Given in the exam:
Ar of Cu = 64 Cu (Copper) = 64
Ar of O x 2 = 16 x 2 =32 O (Oxygen) = 16
Ar of H x 2= 1 x 2 =2 H (Hydrogen) = 1
Mr Cu(OH)2 = 98
Times two because it is inside the
bracket…read more

Slide 3

Preview of page 3

Here's a taster:

IMPORTANT!
If you didn't know it before well you know now!
Bracket ­ multiply everything inside
- only applies to the number
________ 4 ___________3
of the element on the left
2______________- number in front applies
to the whole formula in this case its two…read more

Slide 4

Preview of page 4

Here's a taster:

The Mole
1 MOLE of any substance contains the same number of particles
If you must know its 6.02 x 10^23 (^ = to the power of)
a mple
Ex
NaCl [ Sodium Chloride]
Ar of Na (Sodium) = 23
Ar of Cl (Chlorine) =35 .5g
1 Mole of Sodium Chloride is 58.5g
Basically it has a unit on the end such as gram.
A'1M' solution contains one mole dissolved into one litre…read more

Slide 5

Preview of page 5

Here's a taster:

Percentage mass
NEED TO
Relative atomic mass
REMEMBER
Total relative molecular mass x 100
x a mple
An e
Percentage mass of Magnesium in Magnesium Oxide
Relative atomic mass of Magnesium = 24
Relative atomic mass of Magnesium Oxide = 24 + 16 =40
24
X 100 = 60 % Ar of Mg = 24
40
Ar of O = 16
So Magnesium makes up 60% of the mass of the
compound…read more

Slide 6

Preview of page 6

Here's a taster:

An exam question on percentage of mass
Find the percentage mass of Nitrogen in Ammonium Nitrate
NH4NO3
Relative molecular mass of Ammonium Nitrate is 80
Relative atomic mass of Nitrogen is 14 x 2 =28 [two Nitrogens]
28
80 X 100 = 35%
35% of Ammonium Nitrate is made of Nitrogen and makes up more than
1/3 of the compound as Nitrogen provides more green, healthier leaves fir
greater development.…read more

Slide 7

Preview of page 7
Preview of page 7

Slide 8

Preview of page 8
Preview of page 8

Slide 9

Preview of page 9
Preview of page 9

Slide 10

Preview of page 10
Preview of page 10

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all resources »