Extraction of Metals (Group II) and their Compounds: General properties, calcium- extraction of calcium, properties calcium, compounds of calcium, uses.

SECOND TERM E-LEARNING NOTES

SUBJECT: CHEMISTRY

CLASS: SSS 3

WEEK 6

TOPIC: METALS AND THEIR COMPONDS

CONTENTS:

1. CALCIUM- EXTRACTION OF CALCIUM,
2. PROPERTIES OF CALCIUM.
3. COMPOUNDS OF CALCIUM AND THEIR USES.

PERIOD 1: CALCIUM

Calcium is just too reactive to happen as free metals in nature. As a substitute it happens abundantly within the state as Calcium trioxocabonate (iv) (CaCO₃)_, in limestone marble, chalk, aragonite, calcite and coral; as calciumtetraoxosulphate (vi) (CaSO₄) in gympsum and anhydrite, as double trioxocarbonate (iv) CaCO_3. MgCO_3. In dolomite; as calcium fluoride CaF_2, in fluorspar and as numerous trioxosilicates (iv). Bones and enamel comprise calcium tetraoxo-sulphate (v).

Extraction of calcium;

Since calcium compounds are very steady, metallic calcium is often extracted electronically from fused calcium chloride, a fluoride is often added to the fused calcium chloride to decrease the melting level from 850^oC to about 650^oC The combination is place in a crucible, lined on the within with graphite which serves because the anode of the cell. The cathode consists of an iron rod which simply touches the floor of the electrolyte. As electrolysis proceeds, metallic calcium collects on the cathode which is progressively reused in order that an irregular of calcium is fashioned on it.

Chlorine is liberated on the anode.

Chemistry of the response: Fused calcium chloride consists of calcium and chloride ions.

On the cathode: the calcium ions obtain two electrons every to change into lowered to the metallic.

Ca²⁺ + 2e^– Ca [Reduction]

On the anode: Two chloride ions hand over an electron every to change into atomic chlorine. The 2 atoms the mix to change into liberated as a gaseous molecule

Cl^– Cl + e^– (oxidation)

Cl + Cl Cl₂

Total electrolytic response:

Ca²⁺_(l) + 2Cl^– Ca_(s) + Cl_2(g)

EVALUATION:

Describe the extraction of calcium

PERIOD 2: PHYSICAL PROPERTIES

CHEMICAL PROPERTIES

Response with air: calcium is a really electropositive and reactive metallic. On publicity to air, it quickly tarnishes and loses its metallic lustre as a result of formation of a white movie of calcium oxide or fast lime on the floor of the metallic. Within the presence of atmospheric moisture and carbon (IV) oxide, some calcium hydroxide and calcium-trioxocarbonate (IV) might also be fashioned.

When calcium is heated in air, it burn with a brick-red flame calcium oxide.

2Ca_(s) + O_(g) 2Ca_(s)

TEST FOR CALCIUM IONS

Flame check: calcium compound give an orange-red color to a non-luminous flame. And produce brick-red flame which seems inexperienced if by means of a blue glass.

Word: Barium offers a pale inexperienced flame whereas strontium offers a brilliant pink flame.

1. with dilute hydroxide: And some drops of sodium hydroxide resolution to an answer of unknown salt. The formation of white precipitate, which is insoluble in extra sodium hydroxide, signifies the presence of sodium hydroxide ions.[mediator_tech]

2NaOH_(aq) +Ca²⁺ Ca(OH)_2(s) + 2Na_(aq)

With ammonium ethandioate: add an answer of ammonium ethandioate to an answer of the unknown salt. The formation of a white precipitate, which is soluble in dilute hydrochloric acid however insoluble in ethanoic acid, signifies the presence of calcium ions,

(NH₄)₂C₂O₄ + Ca²⁺_(aq) CaC₂O_4(s) +2NH_4(aq).

Ammonium trioxocarbonate (iv) could also be used as an alternative of utilizing ammonium ethandioate i.e.

(NH₄)₂CO_3(aq) + Ca²⁺_(aq) CaCO_3(s) + 2HN⁺_4(aq)

Word: Barium and strontium salt endure related reactions with ammonium ethandioate and ammonium trioxocarbonate (iv)

EVALUATION:

1. State 4 bodily properties of calcium

1. Clarify why calcium hydroxide doesn’t dissolve in sodium hydroxide whereas aluminium hydroxide does.

PERIOD 3: USES OF CALCIUM AND CALCIUM COMPOUNDS

1. It’s used as oxidant in nonetheless casting and copper alloys.
2. It’s used within the manufacture of calcium fluoride.
3. It’s used within the extraction uranium.
4. Calcium oxide is used for the manufacturing of bleaching powder and caustic soda
5. Calcium oxide is used as desicant within the laboratory
6. Calcium oxide is used within the manufacturing of morta and cement.
7. calcium trioxocarbonate (iv) is used for the manufacture of cement
8. calcium tetraoxosulphate (vi) is used for making plaster of paris.
9. Calcium hydroxide is used for softening onerous water.

EVALUATION

1. Record the bodily properties of calcium.
2. Define the final properties of alkaline earth metals.
3. Focus on the chemical properties of calcium.

PERIOD 4: Tin

TIN

Tin doesn’t happen naturally as free aspect, the principle supply is the mineral cassiterite or tinstone. SnO₂.

Tin stone is present in Malaysia, Indonesia and Bolivia. In Nigeria, tin was mined in jos plateau in 1903 Nigeria is the present largest producer of tin and is current exporting a lot of the 13000 tonnes produced yearly.

EXTRACTION OF TIN

The phases concerned within the extraction of tin are as follows

1. The ore SnO₂ is first concentrated by crushing and washing with water.
2. Impurities like unstable oxides, sulphur, arsenic and antimony are eliminated by roasting the concentrated ore in air.
3. The molten tin is impure and, may be refined to about 99.9 purity by heating gently it on a sloping floor. The impurities that are uncovered to air as molten tin flows are transformed to oxides left behind as a scum.

PHYSICAL PROPERTIES

Tin exists in three allotropic types, which have completely different densities. At room temperature, tin exists as white tin.

13.2⁰C

13.2⁰C

Gray tin white tin rhombic tin

CHEMICAL PROPERTIES

1. Response with oxygen: Tin is reactive and solely combines with oxygen above 1200^oC. it doesn’t mix with nitrogen and carbon.

Sn_(s) + O₂ SnO_2(s)

1. Response with non-metals: Tin combines chlorine when heated to provide tin(iv)chlorine

Sn_(s) + 2Cl_2(g) SnCl_4(s)

1. Response with acids: Tin reacts slowly with dilute hydrochloric acid quickly with the concentrated acid give tin (ii)chloride

Sn_(s) + 2HCl_2(aq) Sn Cl_2(saq + H_2(g)

With dilute tetraoxoculphate(vi) acid hardly any response is noticed, however with the recent concentrated acid, sulphate(iv) oxide is developed

Sn_(s) + 2H₂SO_4(aq) SnSO_4(aq) + SO_2(g) + 2H₂O_(l)

The response of tin with trioxonitrate (v) acid will depend on the focus and temperature of the acid.

Response with alkalis: Tin dissolves in concentrated resolution of alkalis to provide trioxostannate(iv) salts and hydrogen.

Sn_(s) + 2NaOH_(aq) + H₂O_(l) Na₂SO_3(aq) + 2H_2(g)

Makes use of of Tin

That is used

1. In alloys and (b) to current iron from corrosion.

SUBTOPIC 3: TRANSITION METALS

Transition metals are between teams 2 and three on the periodic desk. They occupy 3 rows i.e. interval 4 to interval 6. There are 10 components in every row. They’re additionally known as the block components as a result of they occupy the block on the periodic desk.

The primary transition sequence ranges from scandium to zinc. They’re ten in quantity and their atoms have 1 or 2 elections within the 4s. All of them have partially crammed 3d-block orbital’s which accounts for his or her particular properties zinc (Zn) and copper (Cu) have utterly crammed three-D orbits and Sc³⁺ ions doesn’t.

Bodily Properties

They’re all metals with excessive densities, excessive melting factors, excessive tensile power and sonority. Mercury Hg is of the three^rd transition sequence. It’s a liquid at room temperature. The properties above are as a result of robust metallic bonds present between the atoms of transition metals. The 45 electrons and 3d electrons offered robust bonding within the atoms. Atomic dimension of transition metals is smaller than these of the s-block components as a result of although each S and D block components have similar variety of shells.

Chemical Properties

Transition metals have the next attribute properties

1. Variable Valency: Transition metals exhibit a couple of valency or oxidation states. A few of them are having as much as 3 completely different oxidation states. That is as a result of electrons within the d-orbital which can be found for bond formation. E.g chromium has atomic quantity 24. Its digital configuration is 1s², 2s², 2p⁶, 3s², 3p⁶, 3d⁵, 4s². It might subsequently type +6 oxidation state by dropping one 4s and hearth 3d electron as in Ok₂,Cr₂, O and +3 oxidation state by dropping one 4s and two 3d electron as in Cr₂ O₃. Additionally, the atomic variety of manganese is 25 and its digital configuration 1s², 2s², 2p⁶, 3s², 3p⁶, 3d⁵, 4s²_.
2. +2 oxidation state as in MnO by dropping two 4s electrons.
3. +4s and two 3d electrons.
4. +6 oxidation state as in MnO₄^2- by dropping two 4s and 4 3d electrons.
5. +7 oxidation state as MnO₄^– by dropping two 4s and 5 3d electrons.
6. Para Magnetism

Substances which might be weakly repelled from a powerful magnetic subject are known as diamagnetic substances whereas these weakly interested in it are known as paramagnetic substance. Ferromagnetic substances have very nice pressure of attraction for magnetic subject. E.g. Iron, cobalt, and nickel. Most transition metals are paramagnetic as a result of unpaired electrons within the atom, molecule or ion of the metals. The variety of unpaired electrons determines the depth of this impact.[mediator_tech]

1. Catalytic – exercise: Catalysts are discovered amongst transition components as nickel, iron, platinum, chromium and manganese. The presence of the valence electrons and d-orbital in atoms of transition metals make them respect catalysts.
2. Advanced ion formation

Transition metals have an excellent skill to type advanced ions. A posh ion has a central place ion linked to a number of different atoms, ions, or molecules known as liquids. The bonding between the central metallic ion and the liquids could also be both predominantly electrovalent or co-ordinates.

An instance of a posh ion is the blue tetrammine copper(ii)ion. {Cu(NH₃)₄}²⁺ during which the central copper(ii)ion is linked by co-ordinate bonding to 4 ammonia molecules.

Transition metallic complexion has six liquids, the liquids are organized octahedrally across the central metallic ion as within the case of hexacyanforate(iii)ion [Fe(Cn)₆]^3- when 4 liquids are current, they might be organized tetrahedrally.

Examples of Advanced ion

NH₃

Zn²⁺

NH₃

H₃N

Tetramine Zinc (ii) ion

NH₃

H₃N

Tetraminecopper (ii) ion

NH₃

H₃N

NH₃

The electrons donated by the liquids often up the unfinished D-orbital and the 4s and 4p orbital. All transition metallic ions are inclined to from advanced ions with water.

1. Color of transition metallic ion

Transition metallic ions are often colored which function a helpful information in figuring out a compound. The colors are related to partially crammed 3d orbital. Zinc and scandium ion are colourless since they don’t have partially crammed 3d orbital.

1. Chemical Reactivity: Transition metals are reasonably reactive. The reactivity decreases throughout the sequence due to the corresponding improve in values of their ionisation power.

Chemical properties of transition ionisation Power: Chemical properties of transition metals doesn’t range from left to proper as within the s-block and p-block aspect as a result of electrons are added to the inside d-orbitals not the outermost orbital as in s and p block components.

Copper (Cu)

Copper is among the transition sequence. It’s comparatively uncreative, like silver and gold it is usually known as noble metals. It’s discovered as a free metallic in some locations on account of stability in air. The main supply of copper is copper pyrites, CuFeS₂, different compounds of copper are Cu₂O cuprite, malachite CuCO₃ Cu(OH)₂

Extraction of Copper

Copper is extracted from any of its sulphide ores e.g copper pyrite, CuFeS₂. The extraction procedures are as follows:

1. The ore is first concentrated by floatation after which roasted in a restricted provide of air. The iron and a few of the sulphur within the ore are oxidised to iron(ii)oxide and sulphur(iv)oxide respectively

CuFeS_2(s) + 4O_2(g) Cu_2(s) + 2FeO_(g) 3SO_2(g)

1. After including silicon(iv)oxide (SiO₂) to the combination, it’s heated within the absence of air and the iron(ii) concentrated to iron(ii) trioxosulphate (iv) which floats on copper(i) sulphate as slag and is eliminated.

FeO_(s) + SiO_(s) FeSiO_3(s)

1. Copper(i)sulphide is left and it’s heated in managed amount of air to supply copper which is about 97-99% pure.

CuS_2(s) + O_2(g) 2Cu_(s) + SiO_(g)

The copper may be additional purified (to 99.95% purity) by electrolysis whereby the impure copper is made anode and pure copper is made cathode whereas copperIItetraoxosulphate(vi) resolution is the electrolyte. Metallic copper (the anode) ionises and migrate to the cathode accepts electrons and get deposited on the cathode. Impurity like silver and gold are collected as anode slime.

Bodily Properties

1. It’s a smooth, pink stable with metallic lustre with relative density 8.95 and melting level 1080⁰C
2. It is rather malleable and ductile with glorious warmth and electrical conductivity.

Chemical Properties

1. Copper is steady in pure air however copper reacts with moist air and progressively will get coated with inexperienced coating of primary copper(ii)tetraoxosulphate(vi), CuSO₄ 3Cu (OH)₂ and trioxocarbonate(iv). If uncovered to moist sea air a coating of primary chloride is fashioned. Copper is quickly oxidised to dam copper(ii)oxide if heated with air.

2Cu_(s) + O_2(g) 2CuO_(l)

1. Copper doesn’t displace hydrogen from dilute acids as a result of it’s decrease than hydrogen within the electrochemical sequence. It neither react with dilute hydrochloric acid or tetraoxosulphate (vi )acid however with sizzling concentrated H₂SO₄ sulphur(iv) is liberated

Cu_(s) + 2H₂SO_4(aq) CuSO_4(aq) + 2H₂O_(L) + SO_2(s)

With dilute trioxonitrate(v )acid (HNO₃), nitrogen(II) oxide (NO) is given OH and nitrogen(iv)oxide NO₂ is liberated with sizzling concentrated HNO₃

3Cu_(s) + 8HNO_3(aq) 3Cu(NO₃)_2(aq) + 4H₂O + 2NO_(s)

Cu_(s) + 4HNO_3(aq) Cu(NO₃)_2(aq) + 2H₂O + 2NO_(s)

1. Most metals displace copper from resolution of its salts as a result of it’s nearly on the base of the exercise sequence.
2. It’s utilized in making alloys like bronze (Cu and Su)₂ brass (Cu, Zu) and cupronickel (CuNi)
3. Copper is utilized in making cooking utensils and colorimeters.

EVALUATION

1. Clarify briefly paramagnetic and diamagnetic substance.
2. Define the chemical properties of copper.
3. What are transition metals?

TEST FOR COPPER (I) ION

1. Flame Check: Cu²⁺, salts give a traits bluish color to a non-luminous flame.
2. Copper (i) ions give blue precipitate of copper(ii) hydroxyle chloride dissolves in extra aqueous ammonia to provide a deep blue resolution on addition of some drops of aqueous ammonia to the answer of the unknown compound.

Cu²⁺_(aq) + 2OH^–_(aq) Cu(OH)_2(s) + 2Na⁺_(aq)

Cu(OH)_2(s) + 4NH₄⁺+ 4OH^–_(aq) Cu(NH₃)_(aq) + 2OH-(aq) + 4H₂O_(L)

1. On addition of few drops of sodium hydroxide resolution to the Cu²⁺ salt resolution a blue gelatinous precipitation insoluble in extra sodium hydroxide is fashioned.

Cu²⁺_(aq) + 2NaOH_(aq) Cu(OH)_2(s) + 2Na⁺_(aq)

USES OF COPPER

1. Copper has one of the best electrical situation properties after silver. It’s used for making electrical wires due to its glorious ductility.
2. It’s utilized in plumbing and roofing and likewise in different metallic works on account of its attractiveness.

GENERAL EVALUATION

OBJECTIVE TEST:

1. Within the extraction of calcium, some calcium fluoride is launched to (a) receive pure merchandise (b) stabilize the electrodes (c) examine the calcium from reacting with chloride (d) act as a temperature depressant.
2. Calcium react immediately with nitrogen to type (a)Ca₃ (b) Ca₂N₃ (c) Ca₃N₂ (d) Ca₃N
3. Orbitals purchase particular stability after they (a) comprise a single election (b) they comprise two electrons of their whole orbits (c)they’re merely or doubly crammed (d) have a vacant orbital.
4. The next are traits of the transition metals except :
5. Variable oxidation states
6. Colored ions
7. Advanced ion formation
8. Excessive tendency to cote observe.
9. Unreactive nature of copper is on account of having.
10. Partly crammed orbitals
11. Partly crammed orbitals and comprises some inert impurities
12. Fully crammed 3 d orbitals
13. A low place within the ECS

ESSAY QUESTIONS

1. Describe the important options of transition metals and their compounds. Utilizing examples from the primary transition sequence.
2. The oxidation variety of copper with compounds is both +1 or +2. Give the title and system of a compound during which copper has

(i) +1 oxidation state

(ii) +2 oxidation state

1. What are alloys? Clarify why alloys are often used in place of the pure metals (b) Give the composition and makes use of of the next. (i) duraln min (ii) smooth solder (iii) Kind metallic
2. (a) what’s the most important supply of aluminium is nature

(b) utilizing a diagram and equations, clarify how pure aluminium is extracted from the above supply

1. State using the next

(a) sodium hydroxide (NaOH)

(b) Calcium dioxide (Ca(OH)₂)

© Tin (Sn)

WEEKEND ASSIGNMET

Examine Compounds of calcium (reference textual content Ababio web page 458 – 450)

WEEKEND ACTIVITY

Write brief observe on CaCO₃ and Ca(OH)₂