Metals - basic
Non-metals - acidic
Metal(metal oxides or hydroxides) + acid → salt + hydrogen (MASH)
Carbonates(basic) + acid → water + salt + carbon dioxide CO2 (CAWCS)
- An exception for ammonium:
Same thing but will give ammonia gas (NH3)
Instead of CO2.
Ammonium is acidic
*Also only metals more reactive than hydrogen will react with acids
Litmus - red in acid, blue in alkali
Thymolphthalein - colorless in acid, blue in alkali
Methyl orange - red in acid, yellow in alkali
Neutralization reaction:
Acid + base → salt + water (BAWS)
Group 1 metals - high reactivity with water
Metal + water → metal hydroxide + hydrogen
Metal + oxygen → metal oxide
Remember - H^+ + OH^- → H2O (ionic equation for the reaction when an acid neutralizes a
soluble base)
, - Acids are proton donors.
- Bases are proton acceptors.
Weak acids ionize partially
Strong acids ionize completely.
Acidic oxides
are formed when a non-metal element combines with oxygen
They react with bases to form a salt and water
When dissolved in water they produce an acidic solution with a low pH
Common examples include CO2, SO2, NO2 and SiO2
Basic oxides
Basic oxides
are formed when a metal element combines with oxygen
They react with acids to form a salt and water
When dissolved in water they produce a basic solution with a high pH
Common examples include CuO and CaO
Amphoteric oxides - behave as both acidic and basic
Common ex - zinc oxide and aluminum oxide
ZnO/Al2O3
Soluble salts preparation: 2 methods
Method A:
1. Heat the acid
2. Add the insoluble base/carbonate/metal in excess until it stops disappearing or
dissolving.
3. Filter the mixture to remove excess base
4. Transfer the solution to evaporating basin
5. Heat it to evaporate water until crystals appear
6. Allow filtrate to dry and crystalise
Method B: Titration
1. Add alkali and thymolphthalein indicator to a conical flask using a pipette.
2. Add acid to the burette, note the start volume.
3. Add acid to the alkali slowly until the indicator changes color.
4. Calculate the volume of the acid required.
5. Repeat the steps without an indicator.
6. Transfer to the basin, to evaporate water using heat.
7. All crystals to form.
, Insoluble salts preparation: - precipitation
1. Mix two soluble salts.
2. Filter it.
3. Wash it.
4. Dry it.
- To identify an insoluble salt you can see whether it has the state symbol “s” or solid state
symbol.
For example: Pb(NO3)2 (aq) + K2SO4 (aq) → PbSO4 (s) + 2KNO3 (aq)
- Equations for insoluble salts is
Bacl(2) + 2AgNO(3) → 2AgCl + Ba(NO3)2
Solubility rules
Periodic group trends:
Group 1
- Reactivity increases down the group
- Less dense than transition metals
- Melting and boiling point decreases down the group
- Density increases down the group
Non-metals - acidic
Metal(metal oxides or hydroxides) + acid → salt + hydrogen (MASH)
Carbonates(basic) + acid → water + salt + carbon dioxide CO2 (CAWCS)
- An exception for ammonium:
Same thing but will give ammonia gas (NH3)
Instead of CO2.
Ammonium is acidic
*Also only metals more reactive than hydrogen will react with acids
Litmus - red in acid, blue in alkali
Thymolphthalein - colorless in acid, blue in alkali
Methyl orange - red in acid, yellow in alkali
Neutralization reaction:
Acid + base → salt + water (BAWS)
Group 1 metals - high reactivity with water
Metal + water → metal hydroxide + hydrogen
Metal + oxygen → metal oxide
Remember - H^+ + OH^- → H2O (ionic equation for the reaction when an acid neutralizes a
soluble base)
, - Acids are proton donors.
- Bases are proton acceptors.
Weak acids ionize partially
Strong acids ionize completely.
Acidic oxides
are formed when a non-metal element combines with oxygen
They react with bases to form a salt and water
When dissolved in water they produce an acidic solution with a low pH
Common examples include CO2, SO2, NO2 and SiO2
Basic oxides
Basic oxides
are formed when a metal element combines with oxygen
They react with acids to form a salt and water
When dissolved in water they produce a basic solution with a high pH
Common examples include CuO and CaO
Amphoteric oxides - behave as both acidic and basic
Common ex - zinc oxide and aluminum oxide
ZnO/Al2O3
Soluble salts preparation: 2 methods
Method A:
1. Heat the acid
2. Add the insoluble base/carbonate/metal in excess until it stops disappearing or
dissolving.
3. Filter the mixture to remove excess base
4. Transfer the solution to evaporating basin
5. Heat it to evaporate water until crystals appear
6. Allow filtrate to dry and crystalise
Method B: Titration
1. Add alkali and thymolphthalein indicator to a conical flask using a pipette.
2. Add acid to the burette, note the start volume.
3. Add acid to the alkali slowly until the indicator changes color.
4. Calculate the volume of the acid required.
5. Repeat the steps without an indicator.
6. Transfer to the basin, to evaporate water using heat.
7. All crystals to form.
, Insoluble salts preparation: - precipitation
1. Mix two soluble salts.
2. Filter it.
3. Wash it.
4. Dry it.
- To identify an insoluble salt you can see whether it has the state symbol “s” or solid state
symbol.
For example: Pb(NO3)2 (aq) + K2SO4 (aq) → PbSO4 (s) + 2KNO3 (aq)
- Equations for insoluble salts is
Bacl(2) + 2AgNO(3) → 2AgCl + Ba(NO3)2
Solubility rules
Periodic group trends:
Group 1
- Reactivity increases down the group
- Less dense than transition metals
- Melting and boiling point decreases down the group
- Density increases down the group
