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Chapter 7: Equilibrium

1. Dynamic equilibrium equilibrium state that has no net change inmacroscopic properties but the forward and reverse reactions are still occurring

at equal rates.

2. The equilibrium position the proportion of product to reactant in thereaction

3. Le Chateliers Principle : A system at equilibrium when subjected to a changewill respond in such a way as to minimize the effects of the change

4. Equi. Vapour pressure : the pressure exerted by a vapor on its liquid when the

rate of condensation is equal to the rate of evaporation in a closed system

5. A liquid boils when its vapour pressure is equal to the external pressure, and itcharacterized by bubbles forming in the liquid body (not only the surface).

6. Enthalpy of vaporization is defined as the energy required to convert one mole

of a substance in its liquid state into one mole of gas. The data is usually under

298 K.

Chapter 8 : Acids and Bases

1. A Bronsted-Lowry acid is a proton donor. It must be able to dissociate and

release a proton.

2. A Bronsted-Lowry base is a proton acceptor. They must have a lone pair of

electrons.

3. An acid and base in a conjugate acid-base pair differ by only one proton.

4. Amphoteric/amphiprotic substances can act as acids and bases.

5. Based on Bronsted Lowry theory, an amphoteric substance is one that musthave a hydrogen that can be released as H+and a lone pair of electrons.

6. A Lewis acid is an electron pair acceptor.

7. A Lewis base is an electron pair donor. (It donates an electron pair to from

dative bond).

*** All Lewis bases are Bronsted Lowry bases. But not all Bronsted Lowryacids are Lewis acids because they do not contain a proton to donate.

8. Alkalis are soluble bases that dissolve in water to form hydroxide ion.

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9. A salt is a compound formed when the hydrogen of an acid is replaced by a

metal of another positive ion.

Measuring pH using universal indicator

pH 0 4 7 10 14

Universal

indicator

Red Orange Green Blue Purple

Description Very

acidic

Slightly

Acidic

Neutral Slightly

basic

Very

basic

10. A buffer solution : resistant to changes in pH when small amounts of acid or

alkali are added to it

11. Buffering capacity : the ability of a buffer solution to resist changes in pH

12. Conditions of titration between acids and bases :

- 0.10 M solutions of acids and bases

- an initial volume of 50.0 cm3 of acid in the conical flask

- acids and bases react in a 1:1 ratio so that equivalence achieved at equal

volumes for these equimolar solutions

13. Equivalence point : Point where neutralization has occurred exactly, so the

solution only contains salt and water

14. Point of inflection : The large rise in pH

15. An indicator is a weak acid/weak base that has different colours depending

on if it is dissociated/undissociated.

Extent of dissociation

Electrical conductivity

- depends on free moving ions-since strong acids/bases dissociate fully,they tend to have a greater concentration

of ions

Rate of reaction

- the more H=ions, the faster the reactionrate with metals, MO, MCO3, MHCO3

pH

- direct measure of concentration of theconcentration of H+ions in the solution

- strong acids have a lower pH than weakacid

Strong and Weak Acidsand Bases

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*** An indicator will be effective at signaling the equivalence point of a titration

when its endpoint coincides with the pH at the equivalence point.

16. End point is the pH value when an indicator changes colour.

17. Equivalence point refers to the pH value when equal amounts of acids andbases have neutralized each other in solution.

Chapter 9 & 19 : Oxidation and Reduction

1. A redox reaction is a chemical reaction in which changes in the oxidation

numbers occur.

2. Oxidation occurs when there is an increase in oxidation number of an element,

reduction occurs when there is a decrease in oxidation number of an element.

3. Oxidation always occurs at the anode; reduction always occurs at the cathode.

In the voltaic cell, the anode has ve charge and the cathode has a +ve charge.

4. Salt bridge completes the circuit. The salt bridge is a glass tube/strip of

absorptive paper that contains an aqueous solutions of ions that enables vecharge to be carried in the opposite directions to that of the electrons. This

neutralizes the buildup of charge and maintains p.d. Normally, NaNO3, KNO3.

5. Measuring standard electrode potentials under standard conditions

- all solutions must have 1.0 M

- all gases must be at a pressure of 100kPa- all substances used must be pure

- temperature is 298 K/25C- If the half-cell does not include a sold metal, platinum is used as the electrode

Chapter 10: Organic Chemistry

1. Nucleophiles are reactants that are electron rich and attracted to a region of

electron deficiency. They have a lone pair ot electrons and may carry a negative

charge.