💥 • Lesson 2.6 : Metals and Reactivity Series (Chem) Flashcards
During this lesson, we will go over the properties and uses of metals, the properties of alloys, the reactivity series, and finally, the corrosion and extraction of metals.
Compare the thermal conductivity of metals and non-metals.
Metals have high thermal conductivity, while non-metals have low thermal conductivity.
Compare the electrical conductivity of metals and non-metals
Metals are good electrical conductors, while non-metals are poor electrical conductors (except graphite).
Compare the malleability and ductility of metals and non-metals.
Metals are malleable and ductile, meaning they can be hammered into shape or drawn into wires.
Non-metals are brittle and break or shatter easily.
Compare the melting and boiling points of metals and non-metals.
Metals generally have high melting and boiling points, while non-metals usually have lower melting and boiling points.
What are the general chemical properties of metals?
Metals react with dilute acids to form salts and hydrogen gas, and with cold water and steam to form hydroxides and hydrogen gas.
How do metals react with dilute acids?
Metals react with dilute acids to produce hydrogen gas and a salt.
Example: zinc + hydrochloric acid → zinc chloride + hydrogen.
How do metals react with cold water?
Some metals (like sodium and potassium) react vigorously with cold water, producing hydrogen gas and a metal hydroxide.
How do metals react with steam?
Some metals (like magnesium) react with steam to produce hydrogen gas and metal oxide.
Example: magnesium + steam → magnesium oxide + hydrogen.
Why is aluminium used in the manufacture of aircraft?
Aluminium has low density, making it lightweight and reducing fuel consumption.
Why is aluminium used in the manufacture of overhead electrical cables?
Aluminium has good electrical conductivity, making it efficient for transporting electricity.
Why is aluminium used in food containers?
Aluminium is resistant to corrosion, ensuring the food stays fresh and the containers last longer.
Why is copper used in electrical wiring?
Copper has excellent electrical conductivity.
What is brass and what are its components?
Brass is an alloy made by mixing copper and zinc.
What is stainless steel and what are its components?
Stainless steel is an alloy made by mixing iron with chromium, nickel, and carbon.
Why are alloys often harder and stronger than pure metals?
Alloys are harder and stronger because the different sized atoms in the alloy disrupt the layers, making it harder for them to slide over each other.
Why is stainless steel used in cutlery?
Stainless steel is is hard and resistant to rusting.
How do the different sized atoms in alloys affect their structure?
The different sized atoms in alloys prevent the layers from sliding over each other, making the alloy harder and stronger than pure metals.
What is the order of the reactivity series?
Potassium, sodium, calcium, magnesium, aluminium, carbon, zinc, iron, hydrogen, copper, silver, gold.
How can the reactivity of metals be described in terms of displacement reactions?
More reactive metals will displace less reactive metals from their aqueous ions.
What happens when magnesium reacts with steam?
Magnesium reacts with steam to form magnesium oxide and hydrogen gas.
What happens when magnesium, zinc, and iron react with dilute hydrochloric acid?
Magnesium, zinc, and iron react with dilute hydrochloric acid to produce hydrogen gas and form their respective metal chloride salts.
What happens when copper, silver, or gold reacts with dilute hydrochloric acid?
Copper, silver, and gold do not react with dilute hydrochloric acid because they are less reactive than hydrogen.
What are the conditions required for the rusting of iron?
Rusting of iron requires the presence of oxygen and water.
What are some common barrier methods to prevent rusting?
Painting, greasing, and coating with plastic.
How do barrier methods prevent rusting?
Barrier methods prevent rusting by excluding oxygen and water from contacting the metal.
How is zinc used in galvanising steel to prevent rusting?
Zinc is used to coat steel in galvanising, providing a barrier to oxygen and water, and also offering sacrificial protection (corroding and losing electrons instead of the metal it’s protecting).
How is iron extracted from hematite in the blast furnace?
By the reduction of iron(III) oxide in the blast furnace.
What is the role of carbon (coke) in the extraction of iron in the blast furnace?
Carbon (coke) burns to provide heat and produce carbon dioxide.
Equation: C + O₂ → CO₂.
What is carbon dioxide reduced to in the blast furnace?
Carbon monoxide.
Equation: C + CO₂ → 2CO.
What is iron(III) oxide reduced to in the blast furnace?
Iron(III) oxide is reduced by carbon monoxide to form iron and carbon dioxide.
Equation: Fe₂O₃ + 3CO → 2Fe + 3CO₂.
What happens to calcium carbonate (limestone) in the blast furnace?
Calcium carbonate decomposes thermally to produce calcium oxide and carbon dioxide.
Equation: CaCO₃ → CaO + CO₂
What is the formation of slag in the blast furnace?
Calcium oxide reacts with silicon dioxide to form slag.
Equation: CaO + SiO₂ → CaSiO₃.
What is the main ore of aluminium, and how is aluminium extracted?
The main ore of aluminium is bauxite, and aluminium is extracted by electrolysis.
