Chapter 4 & 5 Flashcards
Forming Metal Ions
- Metals lose electrons to form positive ions (cations).
- Number of electrons lost = group number (for main-group metals).
Metallic Bonding Model
- Metals consist of cations in a sea of delocalized electrons.
- Electrostatic attraction holds cations and electrons together.
- Explains properties like conductivity and malleability.
Metallic bonding property - Metals are hard
Strong forces hold metal ions and free electrons together.
Metallic bonding property - Metals have high boiling points
Strong forces between metal ions and free electrons need lots of heat to break.
Metallic bonding property -
Layers of ions can slide, but free electrons still hold them together.
Metallic bonding property - Metals are dense
Metal ions are packed closely together.
Metallic bonding property - Metals conduct electricity
Free-moving electrons carry charge through the metal.
Metallic bonding property - Metals conduct heat
Packed ions and free electrons pass on heat quickly.
Metallic bonding property - Metals are shiny (lustrous)
Free electrons reflect light.
Metallic bonding property - Metals react by losing electrons
Electrons are easily removed because the nucleus has a low core charge.
Limitations of metallic bonding model
The metallic bonding model cannot explain:
1. The range of melting points.
2. Differences in electrical conductivities.
3. The magnetism of cobalt, iron and nickel.
4. Differences in hardness of metals.
5. The different densities of metals.
Reactivity of Metals - Series and Reactions
- Reactivity Series ranks metals by reactivity.
- More reactive metals lose electrons more easily.
- Metals react with oxygen, water, and acids.
Extraction of Iron from its Ore
- Blast furnace process: iron ore + coke + limestone.
- Produces molten iron and slag.
Properties of Ionic Substances - Hardness
Used in houses, bones and plasterboard
Properties of Ionic Substances - High Melting Point
Used to line furnaces and make engine parts
Properties of Ionic Substances - Electrical Conductivity
can be used to make batteries
Properties of Ionic Substances - Other uses
they have other useful properties that can be used in cooking or germ killing.
Ionic bonding Model
Strong electrostatic attraction between positive cations and negative anions
Ionic bonding property - High melting/boiling point
The electrostatic attraction between the cations and the anions is very strong.
Ionic bonding property - Hard and brittle, crystalline structure.
rearranging ions causes repulsion between like
charges.
Ionic bonding property - Conducts electricity
- in the molten and aqueous
states but not the solid
state. - Ions are mobile when molten or dissolved but not when solid
Ionic bonding property - Dissolves in polar solvent
Cations and anions are more attracted to polar solvents than to each other.
Limitations of the Ionic Bonding Model
The ionic bonding model cannot explain all of the features of ionic substances, such as:
1. The different solubilities of ionic substances.
2. The differences in shape of the crystals.
Formation of Ionic Substances - Evaporation
as water evaporates ions crystallise into ionic compounds.
Formation of Ionic Substances - Precipitation
ionic compounds can be precipitated when mixing two solutions. (mixing two solutions forms solids)
Formation of Ionic Substances - Freezing
molten salts can solidify on cooling.
Formation of Ionic Substances - Electron Transfer
a reaction between highly reactive metals and non-metals.
Chemical Formula of Ionic Compounds - Rules
- Write the cation first
- Identify charges on each ion
- Balance charges to make the compound neutral
- Use subscripts for the number of atoms
- For polyatomic ions, use brackets if there are multiples
Ionic Compounds
- Many ionic substances are soluble in water.
- Ions are held by strong electrostatic forces in three-dimensional ionic lattices.
Water as a solvent of ionic compounds
- If the attraction is strong enough, the water molecules can pull the ions out of the lattice.
- The ions are then surrounded by water molecules and are hydrated.
Dissociation
This process of separating
ions
Precipitation reactions
- Occur if ions in solution combine to form a new compound that is
insoluble in water. - Used to remove minerals from drinking water,
to remove heavy metals from
wastewater and in making pigments.
Full equation
shows formulas and states for all the reactants and products:
Ionic Equations
leaves out the spectator ions that are not changed.
Spectator Ions
Ion that remains unchanged and present in the same form on both sides of the equation
How to write Ionic Equation
Full equation:
NaCl(aq) + AgNO₃(aq) → NaNO₃(aq) + AgCl(s)
Step 1 – Write the full ionic equation:
Na⁺(aq) + Cl⁻(aq) + Ag⁺(aq) + NO₃⁻(aq) → Na⁺(aq) + NO₃⁻(aq) + AgCl(s)
Step 2 – Remove the spectator ions (Na⁺ and NO₃⁻):
These ions appear on both sides and don’t change.
Net ionic equation:
Ag⁺(aq) + Cl⁻(aq) → AgCl(s)
Circular Economy
- economy in which waste and pollution is eliminated, products at the end of life are reused, repaired or recycled, and the environment is not harmed
- raw materials are
converted into products that are
used and then discarded as waste
1. Collect them
2. Melt them down
3. Make new bottles or products
Linear Economy
is the process by which a material is made from start to finish by a manufacturer and
where the material is not reclaimed to reuse;
