Metals And Reactivity Series

Question 1

What is the general equation for a metal reacting with air?

Answer 1

Metal + oxygen = metal oxide

Question 2

How does K (potassium) react with air when heated?

Answer 2

Burns with lilac flame

Question 3

How does Na (sodium) react with air when heated?

Answer 3

Burns with a bright yellow flame

Question 4

How does Ca (calcium) react with air when heated?

Answer 4

Burns with a brick red flame

Question 5

How does Mg (magnesium) react with air when heated?

Answer 5

Burns with a bright white flame leaving a white ash

Question 6

How does Al (aluminium) react with air when heated?

Answer 6

Sheets do not burn easily.

Powdered aluminium burns with white sparks leaving a white solid.

Question 7

How does Zn (zinc) react with air when heated?

Answer 7

Burns leaving a yellow solid which turns white when cooled.

Question 8

How does Fe (iron) react with air when heated?

Answer 8

Sheets of iron do not burn quickly.

Iron wool or iron filings burn with yellow sparks leaving a black solid.

Question 9

How does Cu (copper) react with air when heated?

Answer 9

Sheets of red brown copper glows red and forms a black layer of copper oxide.

May also be a blue-green flame.

Question 10

What is the general equation for when more reactive metals react with water?

Answer 10

Metal + water -> metal hydroxide + hydrogen

Question 11

How does K (potassium) react with water?

Answer 11

Floats, moves rapidly around the surface. Bursts into lilac flame. Bubbles of gas released, colourless solution formed. Heat is released. Potassium disappears at the end.

Question 12

How does Na (sodium) react with water?

Answer 12

Floats, moves rapidly around the surface. So much heat released that Na melts into a sphere of molten metal. Sodium disappears. Colourless solution formed.

Question 13

How does Ca (calcium) react with water?

Answer 13

Ca granules burn, bubbles of gas evolved. Beaker feels warm. Calcium disappears. Colourless solution with a white ppt Ca(OH)2

Question 14

How does Mg (magnesium) react with water?

Answer 14

Very few bubbles even after several days.

Question 15

How does Al (aluminium) react with water?

Answer 15

No reaction

Question 16

How does Zn (zinc) react with water?

Answer 16

No reaction

Question 17

How does Cu (copper) react with water?

Answer 17

No reaction

Question 18

How does Fe (iron) react with water?

Answer 18

Rusts after a few days.

Question 19

What is the general equation for when a metal reacts with steam?

Answer 19

Metal + steam -> metal oxide + hydrogen

Question 20

How does Mg (magnesium) react with steam?

Answer 20

Reacts when heated. Produces a very bright white light. Heat given out. A white powder remains.

Question 21

How does Al (aluminium) react with steam?

Answer 21

Aluminium foil will not react. Small pieces will react when the oxide layer is taken off. Aluminium powder reacts when heated to form a white powder.

Question 22

How does Zn (zinc) react with steam?

Answer 22

Reacts when heated. Glows as steam is passed over, producing a yellow powder. Heat is given off. Yellow powder becomes white when left to cool.

Question 23

How does Fe (iron) react with steam?

Answer 23

Iron must be heated until it glows red before the steam is passed over. Reacts to form a black solid.

Question 24

How is reactivity of metal related to their tendency to form positive ions?

Answer 24

More reactive metals have a greater tendency to lose electrons and form positive ions. The further the outer electron is from the nucleus then the more easily it is lost and the more reactive the metal is.

Question 25

What is a displacement reaction?

Answer 25

When a more reactive metal takes the place of a less reactive metal in a compound.

Question 26

List the reactivity series

Answer 26

K (please)
Na (send)
Li (little)
Ca (Charlie’s)
Mg (monkeys)
Al (and)
Zn (zebras)
Fe (in)
Sn (tin)
Cu (cages)

Question 27

What is an ore?

Answer 27

A rock which contains a metal compound from which the metal can be extracted.

Question 28

What two processes can be used to extract metals from ore?

Answer 28

Electrolysis (for metals more reactive than carbon).

Reduction via heating with carbon (for metals less reactive than carbon).

Question 29

What is Phytomining?

Answer 29

The use of plants to absorb metal compounds from soil as part of metal extraction.

Question 30

What steps are involved in phytomining?

Answer 30

Plants (e.g. rapeseed) are grown on ground that contains low-grade ores, so the metal is removed from the ore and enters the plant.

The plants are harvested, dried, and then burned to produce an ash, which is rich in metal compounds.

An acid such as sulfuric acid is added to the ash and insoluble metal compounds react to produce a solution containing soluble copper compounds. The solution is called a leachate.

The metal can then be obtained by adding scrap iron to the leachate solution, and a displacement reaction will occur. For example, to extract copper.

Fe (s) + Cu 2+ (aq) -> Fe 2+ (aq) + Cu (s)

The iron is more reactive than the copper and so the copper is displaced my the iron.

Question 31

What ire the advantages and disadvantages to phytomining?

Answer 31

Phytomining avoids the noise and dust pollen, and the large amount of energy required for traditional mining, thus is better for the environment. Energy is also produced as the plants are burned.

However, it is a slow process. Plants take time to grow and can only be harvested at certain times of the year.

Question 32

Explain how you would carry out an experiment testing how different metals react with water.

Answer 32

Cut a piece of sodium and place it in water. It is very soft and shiny when freshly cut. It shoot’s across the surface of the water, forms a small ball, floats, fizzes and dissolves.

Drip indicator solution into the water. Green blue, pH 7.7

Repeat with lithium and potassium. Lithium is less reactive than sodium and potassium is more reactive than sodium.

Collect a test tube and half fill with water. Add 4 granules of calcium and hold a second, dry test tube over it upside down to collect the gas evolved. Bubbles of gas are released and the test tube feels warm, exothermic reaction. Calcium sinks and rises.

Test the gas by inserting a lit splint into the test tube. Makes a squeaky pop, hydrogen.

Add 3 drops of indicator into the solution. It is green blue, an alkali.

Repeat the experiment using magnesium. Less reactive, bubbles of hydrogen gas form slower. More vigorous with steam.

Question 33

How would you test the reactivity of iron?

Answer 33

Half full separate test tubes with copper (II) sulfate, magnesium sulfate and zinc sulfate solutions.

Add a piece of iron to each tube.

Leave for 3 minutes, record observations.

Question 34

How would you test the reactivity of Zinc?

Answer 34

Half fill separate test tubes with copper (II) sulfate, magnesium sulfate, and iron (II) sulfate solutions.

Add a piece of zinc to each test tube.

Leave for 3 minutes and record observations.

Question 35

How would you test the reactivity of copper?

Answer 35

Half fill test tubes with zinc sulfate, magnesium sulfate and iron (II) sulfate solutions.

Add a piece of copper to each test tube.

Leave for 3 minutes.

Question 36

How would you test the reactivity of magnesium?

Answer 36

Half-fill separate test tubes with copper (II) sulfate, zinc sulfate and iron sulfate solutions.

Add a piece of magnesium to each test tube.

Leave for 3 minutes and record observations.