WEEK9 - Topic 11

Part 1: Acid and Bases: Definitions of acids & bases, Conjugate acids & bases, Reactions of acids, Salts

Part 2: Electrolytes and nonelectrolytes: Ionisation of electrolytes, Strong and weak electrolytes,Ionisation of salts, Introduction to pH

Part 3: Titration and neutralisation: Total and net ionic equations

 

Part 1: Acid and Bases: Definitions of acids & bases, Conjugate acids & bases, Reactions of acids, Salts

Key Concepts

1. Definitions of acids & bases
2. The concept of Conjugate acids & bases
3. The main Reactions of acids
4. Salts 

Arrhenius acid : 물에녹아서 H+ 내놓는 물질

Arrhenius base : 물에 녹아서 OH-를 내놓는 물질

(한계 : 수용액에서만 정의 가능, 암모니아 NH3는 물에 녹아 염기성을 띠지만 OH-를 내놓지 않음)

 

Brensted Lowry acid : H+ donor 

Brensted Lowry base : H+ acceptor 

(acid-conjugate base/ base-conjugate acid)

(strong acid has weak conjugate base , strong base has weak conjugate acid)

 

Lewis acid : lone pair electron acceptor (electrophile)

Lewis base : lone pair electron donor (nucleophile)

 

Reaction of Acids

 

1. Acid + Metal -> Salt + H2 gas

2. Acid + Base -> Salt + H2O water (neutralisation)

3. Acid + Meltal oxides -> Salt + H2O water

4. Acid + Metal Carbonate -> Salt + H2O water + CO2 gas

(H2CO3 will not be generated because they are unstable, instead H2O and CO2 will be produced)

 

 

 

 

Part 2: Electrolytes/nonelectrolytes: Ionisation of electrolytes, Strong & weak electrolytes, Ionisation of salts, Intro to pH

 

Key Concepts 

1. Electrolytes and non electrolytes
2. Strong and weak electrolytes
3. Ionisation of salts
4. pH

-Electrolyte : 물에 녹아 이온 상태로 존재해서 전류가 통하는 물질 (전해질)

(Strong electrolyte -> 물에서 100% 이온으로 존재하는것 

Weak electrolyte -> 물에서 부분적으로 이온으로 존재하는 것)

 

-Salt -> Dissociation (물에 녹아 cation + anion이 되는 것)

-Acid & Base -> Ionisation (not dissociation ! 용어를 다르게 사용한다!)

: Acid (물에 녹아 H3O+ hydronium ions + anion)

: Base (물에 녹아 OH- + cation)

 

 

 

 

pH = power/ amount of H+ (H3O+)

pH = -log[H+]

pOH = -log[OH-]

pH+pOH = 14

 

The amount of sig figs you have will be the amount of decimal places pH and pOH should be rounded to

Part 3: Titration and neutralisation: Total and net ionic equations

 

Key Concepts

1. Titration
2. Neutralisation
3. Total and net ionic equations

A titration is a technique used to work out the concentration of an unknown solution

When you know the concentration of another solution

 

You carefully add the known solution to the unknown solution until the reaction is complete

 

You may need to use indicator to signal the end of the reaction