The document describes different types of acids and bases. It defines acids as substances that produce hydrogen ions (H+) in aqueous solution, and bases as substances that produce hydroxide ions (OH-). Examples of common acids include sulfuric acid, nitric acid, hydrochloric acid and ethanoic acid. Examples of bases are metal oxides and metal hydroxides. The document also discusses the reactions of acids and bases, including metal-acid reactions, and the uses of some common acids and bases.

1. Ethanoic acid (found in vinegar)
 CH₃COOH
 CH₃COO¯ (aq)
 H⁺ (aq)
Hydrochloric acid
 HCl
 Cl¯ (aq)
 H⁺ (aq)
Nitric acid
 HNO₃
 NO₃¯ (aq)
 H⁺ (aq)
Sulfuric acid
 H₂SO₄
 SO₄²¯ (aq)
 H⁺(aq)
Metal + acid -> salt + hydrogen
- Unreactive metal (Copper & Silver) add to dilute acids -> no reaction
- Concentrated nitric acid + metal (Eg. Copper) -> no hydrogen produced, only nitrate (salt) &
water & nitrogen gas
- Lead DO NOT react with dilute HCl & dilute Sulfuric acid
 Layer of lead(II)chloride / lead(II)sulfate formed from initial reaction between lead & dilute
acid
 layer not soluble in water, quickly form coating around metal
 coating protect metal from further attack from acid
Carbonate + acid -> salt + H₂O + CO₂
Metal oxide / hydroxide + acid -> salt + water (react same way)
Acid Uses
Sulfuric - make detergent
- make fertilizers
- found in car batteries
Ethanoic (in vinegar) - to preserve food
- In making adhesives (sticky) Eg. glue
Hydrochloric (HCL) - in leather processing
- for cleaning metals

2. Bases are any METAL OXIDE / METAL HYDROXIDE.
- contain either oxide ions ( O²¯ ) / hydroxide ions (OH¯)
- reacts with acid give salt & water only
Base + acid -> salt & water
- oxide / hydroxide ions from bases react with hydrogen ions from acid form water
Alkali is base that is soluble in water.
All alkalis produce hydroxide ions when dissolved in water.
When ammonia gas dissolve in water, ammonium ions & hydroxide ions are formed.
 Ammonia + water -> ammonium ion + hydroxide ion
Alkali + acid -> salt & water (neutralization)
 hydrogen ions from acid + hydroxide ions from alkali react form water
Alkali heated with ammonium salt give off ammonia gas.
 alkali + ammonium salt -> ammonia (alkali, pungent smell) + salt + H₂O
Alkalis react with solution of 1 metal salt to give metal hydroxide + another metal salt
 alkali +salt (metal a ) -> metal hydroxide(appears as precipitate if insoluble in water) + salt
(metal b)
Uses of bases & alkalis
Ammonia solution
- in window cleaning solutions
- in fertilizers
Calcium oxide
- in neutralizing acidic soil
- to make iron, concrete & cement
Magnesium hydroxide
- in toothpaste to neutralize acid on teeth
- in antacids, relieve indigestion
Sodium hydroxide
- in making soaps & detergent
- in industrial-cleaning detergents

3. Concentration can be changed but strength cannot be changed.
Concentration – how much a substance is dissolved in 1 dm³ of the solution?
Strength – how easily acid / alkali dissociates when dissolved in water
 strong acid dissociate easily (HCL)
 Weak acid does not fully dissociate (Ethanoic) – much lower concentration of hydrogen ions
in solution
HCL strong acid no matter diluted / concentrated
Ethanoic weak acid no matter diluted / concentrated
PH value
- calculated by no. of hydrogen/ hydroxide ions present in solution
- acids with smaller value -> higher concentration of hydrogen ions
- alkalis with bigger value -> higher concentration of hydroxide ions
Soil PH
- plants grow best in neutral / slightly acidic soil
- plants do not grow when soil too acidic
 happens when too much fertilizers added / acid rain
- chemicals added to soil to raise PH
 soil too acidic, treated with base : quicklime (calcium oxide) or slaked lime (calcium
hydroxide)
 known as “liming” the soil
 but adding too much base will make soil too alkaline and unsuitable for plant growth
Indicator Colour in acidic solution pH range which indicator Colour in alkaline
changes colour solution
Methyl Orange Red 3-5 Yellow
Screened Methyl Violet 3-5 Green
Orange
Litmus Red 5-8 Blue
Bromothymol blue Yellow 6-8 Blue
Phenolphthalein Colorless 8-10 Pink

4. Oxides
- many acids & alkalis form by dissolving oxides in water
- compound of oxygen & another element
- 4 types
 amphoteric oxides
can behave as both basic / acidic oxide
Eg. Zinc oxide
can react with both acids or bases to form salt and water formed only
 neutral oxides
show neither basic / acidic properties
Eg. Water, Nitric oxide, carbon monoxide
 acidic oxides (non-metals)
may dissolve in water form acids
Carbon dioxide -> carbonic acid
Sulfur trioxide -> sulfuric acid
Phosphorous (V) oxide -> phosphorous acid
does not react with acids
react with alkalis to form salt & water
Example: Silicon (IV) oxide
solid at room temperature
does not dissolve in water
react with sodium hydroxide form sodium silicate (salt)
 basic oxides (metals)
mostly insoluble in water
few oxide dissolve readily in water (called alkalis) (Eg. sodium oxide & potassium oxide)
PAGE 186 DIAGRAMS!!!

5. Sulfur dioxide
- acidic oxide
- important for manufacture of sulfuric acid
- Properties & uses
1. as bleaching agent
decolorize colored compounds, cause them to turn pale/ white
SD bleach colour compounds by removing oxygen from them
Substance like SD that remove oxygen from other substances -> called reducing agent
Eg. Wood pulp to paper
 Wood pulp colored due to dyes containing oxygen
2. as food preservative
SD poisonous to all organisms (esp. bacteria)
In food industry, SD added to food in small amt.to prevents growth of mould & bacteria.
Minute amt. sufficient to kill bacteria not humans but still poisonous so must strictly control
amt. added
Sulfuric acid
- one of most widely used acids
- cheapest and most readily available strong acid
- Properties & uses of sulfuric acid
1. Manufacture fertilizers (Eg. Ammonium sulfate, superphosphate)
most important use
A. S. -> salt formed when sulfuric acid reacted with alkali ammonia
Super. -> manufactured by reacting raw material calcium phosphate Ca₃(PO₄)₂with
concentrated sulfuric acid (combi. of 2 calcium salts)
2. Manufacture detergents
3. Battery acid in cars
dilute s. acid used in batteries for cars
lead & lead(IV) plates fitted in batteries
when s. acid, lead & lead(IV) plates react, electrical energy produced -> starts car engine
4. Used for making synthetic fibers & making paint & pigments
SEE PAGE 190 CONCEPT MAP!!!