Metal Chemistry

Metal Chemistry

# Properties of Metals

1. Physical Properties:

• General properties: Conductive of electricity and heat, metallic luster, malleable.

• Specific properties:

• Density:

• Lowest: Lithium (Li)

• Highest: Osmium (Os)

• Melting point:

• Lowest: Mercury (Hg)

• Highest: Tungsten (W)

• Hardness:

• Softest: Cesium (Cs)

• Hardest: Chromium (Cr)

2. Chemical Properties:

• Reducing Property: Metals are easily oxidized.

• Reactions with Nonmetals:

• Chlorine: Metal + Cl2 -> Chloride salt

• Oxygen: Metal + O2 -> Oxide (except Au, Ag, Pt)

• Sulfur: Metal + S -> Sulfide salt

• Reactions with Acids:

• Hydrochloric acid (HCl) and dilute sulfuric acid (dilute H2SO4):

• Metal + HCl/dilute H2SO4 -> Salt + H2 (hydrogen gas)

• Note: Metals located before H in the activity series react.

• Nitric acid (HNO3) and concentrated sulfuric acid (concentrated H2SO4):

• Metal + HNO3/concentrated H2SO4 -> Salt + reduced product + H2O

• Note: All metals (except Au, Pt) react.

• Reactions with Water:

• Strong metals (IA, IIA, except Be, Mg): Metal + H2O (room temperature) -> Base + H2

• Medium metals (Mg, Fe, Zn,…): Metal + H2O (high temperature) -> Oxide + H2

• Weak metals (Ag, Au,…): Do not react with water at normal and high temperatures.

• Reactions with salt solutions: Strong metal + salt -> Weak metal + new salt.

• Note: Strong metals (located before Al) react with water at room temperature.

3. Metal Corrosion:

• Definition: The destruction of metals due to the effects of the surrounding environment.

• Types of corrosion:

• Chemical corrosion: Metal reacts directly with the environment.

• Electrochemical corrosion: Metal reacts with electrolytes.

• Corrosion prevention methods:

• Surface protection: Painting, plating, enameling,…

• Electrochemical protection: Connecting the metal to a metal with stronger reducing properties.

4. Metal Production:

• There are 3 methods:

• Electrolysis of molten salts: Used for metals located before Al in the activity series.

• Electrolysis of solutions: Used for metals located after Al in the activity series.

• Pyrometallurgy: Used for metals located before H in the activity series.

• Hydrometallurgy: Used for metals located after H in the activity series.

5. Some common metals:

• Form alkaline solutions when reacting with water at room temperature: K, Na, Ba, Ca.

• Do not react with HNO3 and concentrated cold H2SO4: Al, Fe, Cr.

Note:

• The activity series of metals is a useful tool for predicting the reactivity of metals.

• Understanding the properties of metals helps us apply them effectively in our lives.