Reactions of metals

Reactions of metals

by Karen Lewis

​representing the elements

​In 1805, John Dalton was the first chemist to come up with the idea of using symbols for the atoms of elements,

Multiple Select

Select all the non metals 

Multiple Choice

Select Carbon Monoxide

Multiple Choice

select water

Multiple Choice

select sulphuric acid

​Reactivity Series of Metals

​Potassium (Pt) P

​Sodium (Na) S

​Lithium (Li) L

​Calcium (Ca) C

​Magnesium (Mg) M

​Aluminium (Al) A

​Zinc (Zn) Z

​Iron (Fe) I

​Tin (Sn) T

​Lead (Pb) L

​Copper (Cu) C

​Silver (Ag) S

​Gold (Au) G

​Platinum (Pt) P

​<<<<<Hydrogen

​<<<<<Carbon

Multiple Choice

Which element is the most reactive? 

• potassium

• gold

• copper

• sodium

Multiple Choice

Which element is the least reactive?

• potassium

• lead

• platinum

• gold

Multiple Choice

What are the elements in group 1 called? 

• alkali earth metals

• alkali metals

• halogens 

• noble gases

Multiple Choice

what re the elements in group 7 called ?

• alkali earth metals

• alkali metals

• halogens

• noble gases

Multiple Choice

what re the elements in group 8 (0) called? 

• alkali earth metals 

• alkali metals 

• noble gases

• halogens 

​Preventing Rusting

​•There are two main methods used to prevent rusting;

–Provide a physical barrier to keep out air and water.

–Provide a sacrificial protection by attaching a more reactive metal to the iron.

​Physical barriers

​•Painting – often used to protect everyday steel objects such as cars, bikes and bridges.

•Oil and grease – suitable for preventing rusting of tools and machinery.

•Plastic coating – expensive.

•Tin plating – used in tin cans. Tin is strong and non-poisonous.

•Electroplating – uses electricity to put a thin coat of metal (e.g. Chromium and nickel) onto iron. Chromium and Nickel are often used. Cutlery and taps are often electroplated.

​Sacrificial protection

​•Where coating a metal would be difficult or impossible a more reactive metal can be attached to the iron or steel so that the more reactive metal reacts with the oxygen instead of the iron rusting.

E.g.   Blocks of magnesium attached to oil rigs in   the north sea.

  Blocks of zinc bolted to the hubs of iron   ships.

​Galvanising

​•Galvanising involves both a physical barrier and sacrificial protection.

•It involves dipping the iron or steel in molton zinc.

•The zinc coating keeps out air and water and if the coating is scratched it is still protected as zinc is a more reactive metal.

•Galvanising is used on;

–Girders for bridges and buildings

–Some car body panels

–Buckets and roofing nails.

Multiple Select

select the two things needed for an object to rust

• oxygen

• carbon dioxide

• acid

• water 

Multiple Choice

which method offers both a physical barrier and a sacrificial barrier to rusting 

• oiling

• painting

• galvanising 

• plastic coating

​Metals and Water

​Group 1 metals - Alkali metals

​

​Lithium + Water >> Lithium Hydroxide + Hydrogen Gas

​Li + H20 >> LiOH + H2

​Sodium + Water >> Sodium Hydroxide + Hydrogen Gas

​Na + H20 >> NaOH + H2

​Potassium + Water >> Potassium Hydroxide + Hydrogen Gas

​K + H20 >> KOH + H2

​ Lithium

​Lightest metal

​Tarnishes when it reacts with Oxygen in the air

Can be cut with a knife

​

Flame test - RED

​Sodium

​Tarnishes when it reacts wit the air (faster than lithium)

​Can be cut easily with a knife

​Flame test - Yellow

​Potassium

​Tarnishes very quickly in air

​stored under oil to keep it away from air

​cut be cut VERY easily with a knife

​Flame Test - Purple

Multiple Choice

what happens to the reactivity of the alkali metals as you move down the group?

• increases

• decreases

• stays the same

Multiple Select

select all that are alkali metals

• magnesium 

• sodium 

• caesium

• boron 

• aluminium

Fill in the Blank

which is the most reactive alkali metal?

Multiple Choice

which indicator would turn blue in the presence of LiOH

• Red Litmus

• Phenolphthalein

• Methyl orange 

• Blue Litmus

Multiple Choice

Which indicator would be best to test the strength of LiOH

• Phenolphthalein

• Red litmus 

• Universal 

• Bromophenol blue

​Metals and Acids

​Metals that are above hydrogen in the reactivity series react with acids releasing hydrogen.

• The reaction is more vigorous than the reaction with water.

• The reason is that acids are compounds with replaceable hydrogen.

​We already looked at making salts!

​

• Metal + acid > metal salt + hydrogen

• ​Mg + HCl > MgCl + H2

  Ca + H2S04 > CaSO4 + H2

• ​

• ​

• Think about how the group 1 react with water. What are your thoughts about reacting them with an acid?

​Displacement Reactions

​Displacement: the action of moving something from its place or position.

​

What do you think a displacement reaction is? ​

​

​Potassium (Pt) P

​Sodium (Na) S

​Lithium (Li) L

​Calcium (Ca) C

​Magnesium (Mg) M

​Aluminium (Al) A

​Zoo (Zn) Z

​Iron (Fe) I

​Tin (Sn) T

​Lead (Pb) L

​Copper (Cu) C

​Silver (Ag) S

​Gold (Au) G

​Platinum (Pt) P

​What happens if…

​

Copper Sulphate + Magnesium

​

​

​This happens ......

​Copper Sulphate + Magnesium > Magnesium Sulphate + Copper

​

​Magnesium is high in the reactivity series than Copper, so it displaces Copper

​

​What about this?

​Magnesium Chloride + Zinc

Nothing happens​!!!!!

​No reaction will take place as Zinc is lower down the reactivity series than Magnesium

Fill in the Blank

Zinc oxide + calcium

Fill in the Blank

Magnesium + iron oxide

Fill in the Blank

Magnesium sulphate + Zinc

Fill in the Blank

Gold + copper oxide

Fill in the Blank

Calcium + copper oxide