Metals

Learning Objectives Use reactivity data to determine a reactivity series Relate extraction method to reactivity of metals Write word/symbol equations for reduction of metal ores with carbon

Put the metals in order of reactivity MetalReaction with dilute acid Reaction with water Reaction with oxygen A Some reactionSlow reactionBurns brightly B No reaction Reacts slowly C No reaction D Violent reactionSlow reactionBurns brightly E Slight reactionReacts with steam only Reacts slowly

Displacement reactions Mg Magnesium SO 4 Cu Copper sulphate The magnesium DISPLACES the copper from copper sulphate SO 4 Mg Magnesium sulphate Cu Copper A displacement reaction is one where a MORE REACTIVE metal will DISPLACE a LESS REACTIVE metal from a compound.

The Thermite reaction Al Aluminium Fe O Iron oxide Aluminium DISPLACES iron from iron oxide Simplified and NOT balanced equation

Pie chart to show the elements present in the earth’s crust

Most elements in the earth’s crust are found as compounds Compounds contain atoms of more than 1 element joined together. There are 2 types of chemical ---- IONIC bonds are formed between a metal + non metal. The metal atom TRANSFERS electrons to the non metal. COVALENT bonds are formed between non metals. The atoms SHARE electrons.

Extraction methods Potassium Sodium Calcium Magnesium Aluminium Carbon Zinc Iron Tin Lead Copper Silver Gold Platinum Metals ABOVE CARBON, because of their high reactivity, are extracted by ELECTROLYSIS Metals BELOW CARBON are extracted by heating them with carbon in a BLAST FURNACE These LOW REACTIVITY metals don’t need to be extracted because they are SO unreactive you’ll find them on their own, NATIVE (not in a metal oxide) N.B. Cu can sometimes be found native Increasing reactivity

Native metals Unreactive elements (Gold, silver and sometimes copper) do not need to be extracted as they are not chemically combined with any other elements.

Iron Hematite (iron oxide, Fe 2 O 3 ) Magnetite Magnetite (iron oxide Fe 3 O 4 )

Minerals in rocks are not pure, but mixed with other substances. To be useful the metal needs to be extracted from the rock. A metal ore is a rock containing enough of the metal compound to make it economic to extract it. This can vary over time as demand/ supplies/ value change. Metal ores

The Blast furnace

Reduction with carbon Zinc, iron, tin, lead and copper can all be extracted from their ores by SMELTING. Metal ore (OXIDE or SULFIDE) is heated to a high temperature with carbon. Carbon DISPLACES the metal. This is a REDOX process, the carbon is OXIDISED (gains oxygen) at the same time the metal ore is REDUCED (loses oxygen)

Equations From an oxide: Iron oxide + carbon  carbon dioxide + iron (Fe 2 O 3 ) 2Fe 2 O 3 + 3C  3CO 2 + 4Fe From a sulfide: Copper sulfide + oxygen  sulfur dioxide + copper oxide (CuS) 2CuS + 3O 2  2SO 2 + 2CuO Copper oxide + carbon  carbon dioxide + copper (CuO) 2CuO + C  CO 2 + 2Cu

Summary: Extracting metals 1)What is an ore? 2)In what form are metals usually found in the Earth? 3)How do you get a metal out of a metal oxide? 4)What is this type of reaction called? Type of metalExtraction processExamples High reactivity (i.e anything above carbon) Middle reactivity (i.e. anything below carbon) Low reactivity