Chapter 6 Reactivity

8/12/2019 Chapter 6 Reactivity

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CAMBRIDGE SECONDARY

ONE SCIENCECHAPTER 6: REACTIVITY


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6.1 METALS AND THEIR REACTIONS WITH OXYGEN

When a metalreacts with oxygen, a

metal oxide is formed.

Metals have differentlevels of reactivitytowards oxygen. Magnesiumis more

reactive thaniron because it reacts

much faster than iron.


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Themetals of Group 1 are more

reactive than other metals.

Group 1 metals must be stored under oilbecause they react vigorously with

oxygenand moisture in the air and can

explode.


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When pieces of lithium, sodium or

potassium are taken out from their

containers, they become dull. Thesurface is covered with metal oxide.

The general word equation for the reaction

of a metal with oxygen:Metal + Oxygen Metal oxide


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Group 1 metals are stored under oil


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6.2 REACTIONS OF METALS IN WATER

Group 1 metals react vigorously with

water.

The general word equation for the reactionof a metal with water:

Metal + Water Metal + Hydrogen

hydroxide


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The reactivity of group 1 metals with

water increases when going down the

group.Potassium is the most reactivewhen compared to lithium and sodium.


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Video on the reactions of group 1 metals

with water:


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Some metals react less vigorously with

water magnesium and calcium.

Some metals that do not react with watermay react with steam. Magnesium reacts

more vigorously withsteamthan water.

The word equation for the reactionbetween magnesium and steam

Magnesium + Steam Magnesium+Hydrogen

oxide


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hydrogen gasmagnesium ribbon

ceramic wool

delivery tube

Bunsen burner

Reaction of magnesium with steam


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6.3 REACTIONS OF METALS WITH DILUTE ACID

When a metal reacts with dilute acid, the

products are a salt and hydrogen.

Different metals have differentlevels ofreactivity in dilute acid.


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6.4 THE REACTIVITY SERIES

Potassium, K

Sodium, Na

Magnesium, Mg

Calcium, Ca

Aluminium, Al

Zinc, Zn

Iron, Fe

Tin, Sn

Lead, Pb

Copper, Cu

Silver, Ag

Gold, Au

Most reactive

Least reactive

Carbon, C


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6.4 THE REACTIVITY SERIES

Metal Reaction with

oxygen

Reaction with

water

Reaction with dilute

acid

Potassium Burns brightly when

heated to form a metal

oxide

Very vigorous

reaction in cold

water to form a

metal hydroxide

Violent reaction and

very dangerousSodium

Calcium Burns brightly in air

when heated to form a

metal oxide

Slow reaction in cold

water to form a

metal hydroxideMagnesium Reaction which

becomes less vigorous

as you go down the listAluminium Slow reaction when

heated to form a metaloxide

Reacts with steam

but not water to forma metal oxide

Zinc

Iron

Lead No reaction with

steam or waterCopper No reaction

Silver No reaction

Gold


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6.5 DISPLACEMENT REACTIONS

More reactive metals can displaceless

reactive metals from their salt solutions.

This is called displacement reaction.If a clean iron nail is placed into a beaker

of copper sulfate solution, the iron nail will

be coated with copper. Ironhasdisplaced copperfrom copper sulfate

solution.


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6.5 DISPLACEMENT REACTIONS

Iron can displace copper from copper sulfate solution


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6.6 USING DISPLACEMENT REACTIONS

Aluminiumis more reactive than iron.

Aluminium will displace iron from solid

iron oxide if it is heated.Aluminium + Iron oxide Aluminium + Iron

oxide


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Using displacement reaction for welding

(thermite reaction)

Rails are needed to be welded where the railway lines are.

The iron oxide and aluminium powder react in a container placed on the rails.

The molten iron produced in the reaction is shaped and used to join the rails

together.


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Carboncan be used todisplace some

metals from their ores.An ore is arock

that contains a metal compound.Carbonwill displace zinc, iron, tin and lead

from their ores.

The iron ore is mainly iron oxide. This reactswith carbonto form ironand carbon dioxide.

Iron oxide + Carbon Iron + Carbon

dioxide


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Using displacement reaction for extraction

of metal

Iron ore and coke (a form of carbon) are added into the blastfurnace.

Iron being displaced from its ore by carbon.

A blast of hot air is blown into the furnace to burn the coke andcreate high temperatures needed for the reaction.

Molten iron collects at the bottom.


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Blast furnace
http://images.yourdictionary.com/blast-furnace


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Chapter 6 Reactivity

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