Metals part 2

Question 1

potassium , sodium , calcium + HCl

Answer 1

violently

Question 2

magnesium , aluminium + HCl

Answer 2

reacts readily

Question 3

zinc + HCl

Answer 3

reacts moderately fast

Question 4

Iron + HCl

Answer 4

reacts slowly

Question 5

lead + HCl

Answer 5

reacts very slowly as a layer of lead chloride is formed and after that stops reacting as it acts as a protective layer

Question 6

extraction of metals

Answer 6

• more reactive metals harder to extract as need tougher methods of extraction
• zinc and below can be extracted by heating with carbon
• aluminium and other metals above form very stable oxides and can only be extracted through electrolysis of their molten oxides

Question 7

decomposition of metal oxides

Answer 7

• reactive metals form very stable carbonates that do not decompose easily when heated
• carbonates formed with less reactive metals are easily decomposed through heating

Question 8

extraction of IRON

Answer 8

-heat haematite with carbon

Question 9

stainless steel

Answer 9

mixture of iron , carbon ,chromium and nickel to make it more resistant to corrosion

Question 10

rusting of iron

Answer 10

iron corrodes in the presence of water and oxygen to form rust .

• can be prevented by layering iron with oil
• can be prevented with sacrificial protection