This aesthetic, neatly typed document contains all the IEB Grade 12 Chemistry SAG Definitions from each section: Quantitative Chemistry, Chemical bonding, Energy Change & Rates of Reactions, Chemical Equilibrium, Acids & Bases, Electrochemistry, and Organic Chemistry
Grade 12 IEB Physical Science: Chemistry (Paper 2) SAG De nitions:
Section A: Quantitative Chemistry:
• Molar mass: The mass in grams of one mole of that substance
• Solution: A homologous mixture of solute and solvent
• Solute: The substance that is dissolved in the solution
• Solvent: The substance in which another substance is dissolved, forming a solution
• Concentration: The amount of solute per unit volume of solution
• Yield: A measure of the extent of a reaction, generally measured by comparing the amount of
product against the amount of product that is possible
Section B: Chemical Bonding:
• Covalent bond: A sharing of at least one pair of electrons by two non-metal atoms
• Non-polar covalent bond (Pure covalent): An equal sharing of electrons
• Polar covalent bond: An unequal sharing of electrons leading to a dipole forming (as a result of
electronegativity di erence)
• Electronegativity: A measure of the tendency of an atom to attract a bonding pair of electrons
• Ionic bond: A transfer of electrons and subsequent electrostatic attraction
• Metallic bonding: Between a positive kernel and a sea of delocalised electrons
• Intermolecular forces: A weak force of attraction between molecules, ions or atoms of noble
gases
Section C: Energy Change & Rates of Reactions:
• Heat of reaction: The net change of chemical potential energy of the system
• Exothermic reactions: Reactions which transform chemical potential energy into thermal energy
fi
, • Endothermic reactions: Reactions which transform thermal energy into chemical potential energy
• Activation energy: The minimum energy required to start a chemical reaction OR The energy
required to form the activated complex
• Activated complex: A high energy, unstable, temporary transition state between the reactants and
the products
• Reaction rate: The change in concentration per unit time of either a reactant or product
• Catalyst: A substance that increases the rate of reaction but remains unchanged at the end of the
reaction
Section D: Chemical Equilibrium:
• Closed system: one in which mass is conserved inside the system but energy can enter or leave
the system freely
• Open system: one in which both energy and matter can be exchanged between the system and
its surroundings
• Reversible reaction: Reaction in which products can be converted back into reactants
• Le Châtelier's principle: When an external stress (change in pressure, temperature or
concentration) is applied to a system in dynamic chemical equilibrium, the equilibrium point will
change in such a way as to counteract the stress
Section E: Acids & Bases:
• Acid: A proton donor
• Base: A proton acceptor
• ionisation: The reaction of a molecular substance with water to produce ions
• Strong acid: An acid that ionises completely in an aqueous solution
• Weak acid: Acid that only ionises partially in an aqueous solution
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Lindyprinsloo. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.19. You're not tied to anything after your purchase.
