Unit 10: Metals Flashcards
List the order of reactivity in the reactivity series
Potassium Sodium Calcium Magnesium Aluminium (Carbon) Zinc Iron Lead (Hydrogen) Copper
List two chemical properties of metals
- They form positive ions
2. They react with acids to form a salt and hydrogen gas
What is an alloy?
A mixture of a metal with another element.
What are some of the benefits of alloys?
- They are generally harder because the atoms in an alloy are of different sizes, meaning that the layers of atoms cannot slide over each other like they normally would.
- They can be made so that they have a lower or higher melting point.
Which metals will react with water?
Potassium down to calcium on the reactivity series.
What is produced when a metal reacts with water?
A metal hydroxide and hydrogen gas.
Ex. Ca + H20 –> Ca(OH)2 + H2
Which metals will react with steam?
Magnesium down to iron on the reactivity series.
What is produced when a metal reacts with steam?
A metal oxide and hydrogen gas.
Ex. Mg + H20 –> MgO + H2
Which metals will react with dilute acids?
Potassium down to iron on the reactivity series.
Note: lead will react slowly but then stop as an unreactive layer will be formed on its surface.
What is produced when a metal reacts with a dilute acid?
A salt and hydrogen gas.
Ex. Zn + 2H+ –> H2 + Zn2+(aq)
How is the reactivity series determined?
By a metal’s tendency to form its positive ion as an aqueous ion or as its oxide.
What effect does heat have on a metal hydroxide?
K and Na will remain stable but all the other metals will decompose to their oxide and water.
What effect does heat have on a metal carbonate?
They will all decompose to their oxide and carbon dioxide.
What effect does heat have a metal nitrate?
Potassium and sodium will react to form a metal nitrous and oxygen gas.
Calcium down to copper will react to form their oxide, nitrogen dioxide and oxygen gas.
Everything below copper will react to form a metal, nitrogen dioxide and oxygen gas.
Why does aluminium appear to be initially unreactive?
Because it has an unreactive aluminium oxide layer which takes time to wear away.
How can a metal be obtained from its ore?
By displacing the metal from a solution of its ions by another metal higher on the reactivity series.
Which metal OXIDES can be reduced by carbon?
Lower than and including zinc on the reactivity series.
How is iron extracted from its ore and what are the essential reactions that take place?
- Iron oxide, carbon and limestone are added into the top of a furnace.
- Air is fed into the bottom of the furnace, reacting with carbon (C + O2 –> CO2).
- This further reacts to form carbon monoxide (CO2 + C –> 2CO).
- The carbon monoxide acts as the reducing agent (Fe3O4 + CO –> 3Fe + CO2).
- The limestone decomposes in the heat (CaCO3 –> CaO + CO2) to calcium oxide and CO2. The CaO forms a slag with the impurities.
- The iron (called pig iron and about 5% carbon) is tapped off at the bottom of the furnace.
How is iron converted into steel?
Oxygen is blown through the molten pig iron to lower the carbon content and other elements are added to give the steel certain properties.
Which process is aluminium extracted by?
From its ore bauxite by electrolysis.
How is zinc extracted?
Zinc is extracted from zinc blende/zinc sulfide.
- The ore is concentrated.
- The zinc sulfide is heated in a furnace to form zinc oxide (2ZnS + 3O2 –> 2ZnO + 2SO2).
- The zinc oxide is then heated in a furnace with carbon and reduced to zinc metal (ZnO + C –> Zn + CO).
