Exam 3 Note Cards

Fun Facts: Aluminum

1. Lightest metal commonly used in commercial applications.

2. Obtained from the energy intensive Bayer process (used to make aluminum oxide from bauxite rocks) and Hall process (used to make aluminum from aluminum oxide)

3. It is the oxide that forms ruby, sapphire, and topaz gemstones

Fun Facts: Alkali Metals

1. Large radii

2. Low ionization energy

3. Low electronegativity

4. Form +1 cations

5. Oxides and hydrides are basic

6. Metal displacement reaction with water: M + H₂0 → M⁺ⁿ + OH^- + H₂ (Alkali metals react vigorously in water, coinage metals (Cu, Ag, Au, Pt) do not react)

Fun Facts: Beryllium

1. Forms covalent bonds because of its relatively small size and ability to attract electrons

Fun Facts: Calcium

1. Is in building materials from concrete to teeth

Fun Facts: Mg²⁺

• In chlorophyll (the green pigment that plants use to make food during a process called photosynthesis)

• Makes the molecule more rigid to permit electron transport for photosynthesis instead of energy loss through vibrations

Goals for Battery Design

1. Small

2. Non-expensive

3. High power

4. Long life

5. Reversible

6. Environmentally friendly

Secondary Batteries

Built w consideration given to minimizing liquid or gas production —> contents of rnx are better contained for recharging

Lithium (Li) - Ion Batteries

Catch fire and not allowed to be shipped as commercial cargo on planes

Parts: electrolyte, cathode (+), Li metal oxide, porous separator, electrolyte, Li ion, Li-Carbon (graphite), Anode (-)

Battery Facts 1

Modern batteries made w solids and pastes (instead of L&G) to avoid losses of material

Battery Facts 2

1. Primary batteries —> Single use

2. Secondary batteries —> Rechargeable

Battery Facts 3

Ineffective batteries —> produce heat (doesn’t work)

**controlling heat dissipation is important practically and for saftey

Battery Facts 4

Lightweight batteries use less dense, higher charge density materials (i.e. Li)

Primary Batteries

• Disposed of after one cycle

• Famous primary batteries include:

  • Common alkaline battery (think Duracell)

  • The inexpensive Zn-C

  • Smaller specialty batteries like Zn-air battery used in hearing aids (although some Zn-air are now rechargeable)

Secondary Batteries

• Reversible (reusable/rechargeable)

• Built with consideration given to minimizing liquid or gas production so that contents of the reaction are better contained in the battery casing for recharging

• Famous secondary batteries include:

  • Lithium-ion batteries in electronics and electric vehicles

  • Lead-acid batteries found in vehicles (gas-powered) that are recharged by an alternator when the engine is running

  • NiMH batteries that have replaced NiCd batteries as the common household rechargeable battery