Metals 12.1 to 12.4

ZnCO3

ZnCO3

________ is formed when zinc reacts with oxygen and carbon dioxide in the air and protects the iron by the barrier method.

molten iron

The ________ is transferred to an oxygen furnace where the conversion to steel takes place.

carbon monoxide

The ________ is the reducing agent and reduces the zinc oxide to zinc:

Bauxite

________ is first purified to produce aluminium oxide Al2O3.

sulfuric acid

Is dissolved in ________ and due to being a base, neutralises it to produce zinc sulfate.

slag

The ________ floats on the surface of the molten iron and is skimmed off.

Pure iron

________ is not useful by itself as it is too soft and rusts very easily.

Copper

________ and iron can also react with oxygen although much more slowly.

Limestone

________ (calcium carbonate) is added to the furnace to remove impurities in the ore.

reactivity series

If the coating is damaged or scratched, the iron is still protected from rusting because zinc preferentially corrodes as it is higher up the ________ than iron.

energy

Collection and transport of material to be recycled requires ________ and fuel.

carbon

The ________ in the graphite anodes reacts with the oxygen produced to produce CO2.

warm

Some metals react with water, either ________ or cold, or with steam.

Hot air

________ is blown in the bottom.

Aluminium oxide

________ is then dissolved in molten cryolite.

Energy use

________ is reduced, especially in the electrolysis of aluminium.

Metals

________ lower down on the series can be extracted by heating with carbon.

Unreactive metals

________ do not have to be extracted chemically as they are often found as the uncombined element.

Brass

________ contains 70 % copper and 30 % zinc.

Zinc

________ is also used to make an alloy called brass.

Oxygen

________ is added which reacts with the carbon forming carbon dioxide and carbon monoxide.

Coke

________ burns in the hot air forming carbon dioxide.

addition of zinc

The ________ makes the alloy much harder and more corrosion resistant than copper alone.

Modern blast furnaces

________ produce approximately 10000 tonnes of iron per day.

Aluminium

________ is a reactive metal, above carbon in the reactivity series.

chemistry of metals

The ________ is studied by analysing their reactions with water, dilute acid and oxygen.

Zinc oxide

________ needs to be molten but has a high melting point.

Iron

________ is extracted in a large container called a blast furnace from its ore, haematite.

molten aluminium

The ________ is siphoned off from time to time and fresh aluminium oxide is added to the cell.

calcium oxide

The ________ formed reacts with the silicon dioxide, which is an impurity in the iron ore, to form calcium silicate.

mixture

The ________ is placed in an electrolysis cell, made from steel, lined with graphite.

acidic silicon

The ________ and phosphorus oxides react with the powdered calcium oxide and from a slag which is mainly calcium silicate:

raw materials

The ________: iron ore (haematite), coke (an impure form of carbon), and limestone are added into the top of the blast furnace.

Carbon monoxide

________ reduces the iron (III) oxide in the iron ore to form iron.

Molten iron

________ is an alloy of 96 % iron, with carbon, phosphorus, silicon and sulfur impurities.

Zinc

________ is used in galvanising, the process of coating a metal such as iron or steel with a protective coating of zinc to prevent corrosion or rusting.

Metals

________ that react with cold water form a metal hydroxide and hydrogen gas.

Unreactive metals

________ such as gold and copper do not react with acids.

The raw materials

iron ore (haematite), coke (an impure form of carbon), and limestone are added into the top of the blast furnace

At the cathode

zinc ions gains electrons (reduction) to produce zinc

It is important to monitor the amount of carbon that has been added to iron

too little and the iron is not strong enough but too much and the iron becomes brittle