Pages in this set

Page 1

Preview of page 1
David Kemp OCR Chemistry A Unit 1: F321


Atomic Structure

(a) describe protons, neutrons and electrons in
terms of relative charge and relative mass;

Proton Neutron Electron
Relative Charge +1 0 -1
Relative Mass 1 1 1/2000


(b) describe the distribution of mass and charge
Within an atom;

Positively charged…

Page 2

Preview of page 2
David Kemp OCR Chemistry A Unit 1: F321


(f) state that 12C is used as the standard
measurement of relative masses;

(g) define the terms relative isotopic mass and
relative atomic mass, based on the 12C scale;

Relative isotopic mass ­ Mass of an atom of an isotope compared with…

Page 3

Preview of page 3
David Kemp OCR Chemistry A Unit 1: F321


(d) calculate empirical and molecular formulae,
using composition by mass and percentage
compositions;

Empirical formula = Mass/Percentage of Composition : Mass/Percentage of Composition
Molar Mass Molar Mass

Then divide by the smallest number of moles to find out the ratio.

Chemical Equations…

Page 4

Preview of page 4
David Kemp OCR Chemistry A Unit 1: F321


(g) deduce stoichiometric relationships from
calculations;

Things to remember:
1. Stoichiometric value determines the ratio between the number of moles of a substance.
2. This ratio does not apply to any other calculation apart from working out the number of
moles. After…

Page 5

Preview of page 5
David Kemp OCR Chemistry A Unit 1: F321


(d) state that an alkali is a soluble base that
releases OH­ ions in aqueous solution;

OH- ions are added to neutralise H+ ions, hence why bases neutralise acids.

(e) state the formulae of the common alkalis:
sodium hydroxide, potassium hydroxide and…

Page 6

Preview of page 6
David Kemp OCR Chemistry A Unit 1: F321


(h) explain that a base readily accepts H+ ions
from an acid: eg OH­ forming H2O; NH3
forming NH4+

(i) explain the terms anhydrous, hydrated and
water of crystallisation;

Anhydrous: Substance containing no water molecules.

Hydrated: Crystalline compound containing water molecules.

Water…

Page 7

Preview of page 7
David Kemp OCR Chemistry A Unit 1: F321


(ii) changes in oxidation number;

If the oxidation number of an element increases, it is oxidised.
If the oxidation number of an element decreases, it is reduced.

(c) use a Roman numeral to indicate the
magnitude of the oxidation state of an…

Page 8

Preview of page 8
David Kemp OCR Chemistry A Unit 1: F321


Ionisation Energy

(a) Define the terms first ionisation energy and
successive ionisation energy;

First ionisation energy ­ Energy required to remove one electron from each atom in one mole of
gaseous atoms.

Successive ionisation energy ­ energy required to remove each electron…

Page 9

Preview of page 9
David Kemp OCR Chemistry A Unit 1: F321


Electrons: electronic energy levels, shells, sub-shells, atomic orbital's, electron
Configuration

(d) state the number of electrons that can fill the
first four shells;

1st shell ­ 2
2nd shell ­ 8
3rd shell ­ 18
4th shell - 32

(e) describe an…

Page 10

Preview of page 10
David Kemp OCR Chemistry A Unit 1: F321


(j) classify the elements into s, p and d blocks.

The s-block of the periodic table consists of the first two groups, plus hydrogen and helium.

The p block of the periodic table is from group 3 to group 0 minus helium…

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all resources »