Gr 11 Physical Science Paper 2 Nov 2024
Previous exam papers were used to compile these notes. @IMPAQ NOV 2019, @IMPAQ
NOV 2020 @IMPAQ NOV 2021, EC/NOVEMBER 2023, EC/NOVEMBER 2022,
EC/NOVEMBER 2021, EC/NOVEMBER 2020. CTSC Revision Booklets_WCED
CONTENT
1. Matter and materials
2. Chemical ...
Physical Sciences
Grade 11
November –
Exam
Paper 2
Previous exam papers were used to compile these notes. @IMPAQ NOV 2019, @IMPAQ
NOV 2020 @IMPAQ NOV 2021, EC/NOVEMBER 2023, EC/NOVEMBER 2022,
EC/NOVEMBER 2021, EC/NOVEMBER 2020. CTSC Revision Booklets_WCED
These are only suggested answers from the memorandums. Some information is repeated,
I want to show you the different ways the same information is asked.
I encourage you to answer the calculation/illustration questions.
Good luck. Juffrou Ansie
IMPORTANT: Term 3's notes must be reviewed again together with these notes. If you did
not purchased term 3's notes, contact Juffrou Ansie.
CONTENT
1. Matter and materials
2. Chemical changes
3. Chemical systems
@Juffrou_Ansie
, 2
System Any object you want to study, for example water in a pot.
Phase, temperature, energy flow
Environment Anything outside your system and that is where the observations and
measurements of the particular system are taken.
Open Matter and energy can leave or enter the system
System
Closed System/ Matter and energy cannot leave or enter the system
Isolated
Enthalpy (H) Enthalpy (H) is the total chemical potential energy content of the
reacting materials.
Enthalpy cannot be measured, but the enthalpy change, ΔH, when
energy is transferred to or from a reaction system and changes from
one enthalpy to another, can be measured.
Enthalpy change Enthalpy change (Δ H), is the transfer of energy to or from a system.
(ΔH) This usually takes place as heat transfer. That is why it is also known
as heat of reaction
This then yields the formula Enthalpy change = enthalpy of products
enthalpy of reactants Δ H = H products H reactants
Heat of reaction= energy of products energy of reactants
ENDOTHERMIC
process.
Energy
EXOTHERMIC process.
Energy
Acids • Taste sour
• It changes BLUE litmus paper to RED
• Increase the concentration of hydrogen ions (H+) in a solution
• Lower the concentration of hydroxide ions (OH-) in a solution
• It has a pH value of LESS THAN 7
@Juffrou_Ansie
, 3
Bases • Tastes bitter and feels soapy
• It changes RED litmus paper to BLUE
• It has a pH value of MORE THAN 7
• Lower the concentration of hydrogen ions (H+) in a solution
• Increases the concentration of hydroxide ions (OH-) in a
solution
MATTER AND MATERIALS
Study the two compounds BH3 and NH3.SACAI JUN 2022
Compare the polarity of the BH3 and NH3 molecules by referring to the polarity of the bonds and
the effect of the shape of each molecule on its polarity.
NH3
• pyramidal
• Has a lone pair and 3 bonding pairs.
• Polar molecule
• Asymmetric shape
BH3
• trigonal plane
• has only 3 bond pairs.
• Non-polar molecule Si
• symmetrical shape
Dative covalent bond
The name of the bond that forms between the nitrogen atom in NH3 and a hydrogen ion (H+).
The table below shows the bond length and bond energy for different bonds between two carbon
atoms.
The relationship between bond length, bond order and bond energy
• As the bond order/bond pairs increase, the bond length decreases and the bond energy
increases.
• As the bond order / bond pairs decrease, the bond length increases, and the bond energy
decreases
• C is the strongest because it has the highest bond energy and the lowest bond length.
@Juffrou_Ansie
, 4
Ammonia (NH3) is used to produce fertilizers. An ammonia molecule
is formed when electrons are shared between three hydrogen atoms
and a nitrogen atom.
Covalent bond= The type of chemical bond that occurs between a hydrogen and nitrogen atom.
5/Five= The amount of valence electrons are in a nitrogen atom.
Write down the Lewis structure for the ammonia molecule.
Ammonia molecule
3 Number of electron pairs (bonding pairs) surrounding the central atom
4 Number of shared pairs in the molecule.
Pyramidal The molecular form
Ammonia readily dissolves in water to form ammonia ions, + NH4 (aq). An
ammonia ion is formed when an ammonia molecule shares a lone pair of
electrons with a hydrogen ion.
The type of bond that forms between an ammonia molecule and a hydrogen ion = Dative
covalent bond
Suggest the formation of an ammonia molecule using Lewis structures.
@Juffrou_Ansie
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