كيمياء لغات – Iron properties للصف الثالث الثانوى 2016

Iron properties

:Physical properties

:Pure iron has no industrial use and characterized by

.It is not very hard and is quite reactive -

.Malleable and Ductile -

.Ferromagnetic -

. Melts at 1500 °C and has density of 7.86 g/cm^3 -

So, some elements, such as carbon, manganese, nickel, chromium, are added to pure iron to from alloys which has many uses

:Chemical

:Effect of Air

.Red hot iron reacts with dry air or oxygen to give magnetic iron oxide

:Effect of water

.Red hot iron (500°C) reacts with water vapor to give, iron oxide and hydrogen

:Effect of non-metals

.Iron reacts with chlorine to give iron III chloride and with sulfur to form iron II sulfide

:G.R

.When iron reacts with chlorine produce iron III chloride, not iron (II) chloride

(Because chlorine is an oxidizing agent which oxidizes iron II chloride in to Iron (III

:Effect of Diluted acids

Iron dissolves in diluted mineral acids to form iron II salts and hydrogen which prevents the formation of iron III salts

.G.R

.when iron reacts with dil. HCI produce iron II chloride not iron (III) chloride

.Because the hydrogen produced reduced reduces what is formed of iron (III) chloride to iron (II) chloride

.G.R

.When iron reacts with diluted H₂SO₄, iron (II) sulphate is formed and not iron (III) sulphate

.Because the hydrogen produced reduced reduces what is formed of iron (III) chloride to iron (II) sulfate

:Effect of concentrated acids

.Iron reacts with hot concentrated sulfuric acid to give iron II sulfate, iron III sulfate, sulfur dioxide, and water

.G.R

.When iron reacts with conc. H₂SO₄, both of iron (II) sulfate and iron (III) sulfate are formed

Because conc. hot sulfuric acid is an oxidizing agent which oxidizes iron to (Fe₃O₄), while, the acid is reduced to SO₂ and H₂O. At the same time, Fe₃O₄ reacts with the acid forming iron (II) sulfate, iron (III) sulfate, and water

:Question

?How can you differentiate between -

.Diluted and concentrated sulfuric acid *

.A piece of iron and another from magnetite *

.Concentrated nitric acid and concentrated sulfuric acid

Iron Oxides

(Iron II oxide (FeO *

(Iron III oxide (Fe₂O_3 *

(Magnetic iron oxide (Fe₃O_4 *

:(Iron II oxide (FeO) (black -

:Preparation of Iron oxide

:”By Heating Iron II Oxalate “FeC₂O₄

(NB: Fe₂O₃ is not formed due to CO is reducing agent.            (Give reason

:By Reduction of Higher Oxides

:NB

:Properties of Iron II oxide

:Action of hot air *

:Action of diluted acids *

.It is black solid, insoluble in water *

.Easily oxidized in hot air *

:(Iron (III) oxide (Fe₂O_{3 -}

 :Preparation *

:First Method

:Second Method 

:Rule

:Except: Fe(OH)₂ which is experimentally difficult

.Question: Write one use of iron II oxide

.Occurrence: it occurs in nature as hematite

:Properties

.it is insoluble in water

.It is used as a red pigments in paints and in rouge

.It reacts with hot conc. acids to give iron III salts and water

:(Magnetic iron oxide (Fe₃O_{4 -}

(a- Occurrence:  It occurs in nature as magnetite, where it is a mixed oxide of (FeO and Fe₂O₃

 .b- preparation: by action of air or water vapor on heated red iron

:By reduction of iron III oxide by hydrogen H₂ or carbon mono oxide CO

:c-   properties

.It has strong magnetic property

.It reacts with hot conc. acids to produce iron II and iron III salts which means that it is a mixed oxide

.G.R: Magnetic iron oxide is a mixed oxide

.It oxidizes when it is heated in air to give iron III oxide

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