Reactions with water

Tests

Calculate the energy Splitting of d-sublevel, if the maximum absorption of visible light ion [Cu(NH₃)₄]₂ corresponds to the vawelength =304nm. 349 kJ/mole

Chemical element that is most similar to silicon in its physical and chemical properties: boron

Define appropriate formula for the following aquachlorobis(ethylenediamine)cobalt (III)ion: [Co(En)₂Cl(H₂O)]²⁺

Define th type of hybridization of the next complex ion [Mn(CN)₆]^4-: sp³d²

Define the dentate of ethylendiamine (NH₂CH₂CH₂NH₂): 2

Determine how much (ml) 0.05 M potassium permanganate solution required for the oxidation of 10 ml of 0.2 M sulfate solution of tin (II) in acid (H₂SO₄) medium: 16

Determine the sequence number of separation of metals on the cathode during electrolysis of a mixture of aqueous containing ions Zn²⁺, Ag⁺, Cu²⁺ of the same concentration: Ag, Cu, Zn

For what allotropic modification of carbon is typical of sp³ – hybridization: diamond

For what p – elements is typically the property of “catenation”: Chalcogens

Germanium is dissolved in a H₂SO₄ with a formation the next product: Ge(SO₄)₂

Metal stands on the cathode during the electrolysis of aqueous solutions: Lead acetate

Molecule with the most durable chemical bond: F₂

Name of coordination compound Ba[Cr(NH₃)₂(SCN)₄] is: barium tetrarodanodiaminechromate (III)

Point the reagent where the silicon is dissolved: HNO₃(conc.)

The charge of central metal in coordination compound [Co(NH₃)₄Cl₂]ClO₄ is equal: +3

The hydrogen can be formed during the electrolysis the follows salt: aqueous solution of sodium nitrate

Tin is dissolved in a HNO₃ with a formation the next product: tin nitrate (II)

What type of hybridization describes the structure of CO₂: sp²

When relation between pH solution of salts SbCl₃ (pH₁) and BiCl₃ (pH₃) which has the same concentration: pH1<pH3

Which of ion is colored: [CuCl₄]^2-

Which of ion is diamagnetic: [Fe(CN)₆]^4-

Which of these molecules are paramagnetic? NO

Define the name of the following coordination compounds:

[Co(OH)(H₂O)₄(NH)₃]Cl₂=amine tetra aqua hydroxo cobalt (iii) chloride

[Pt(H₂O) ₄][PtCl₄]=tetra aqua platinum (ii) tetra chloro palatinate (ii)

Ag[HgI₄]=silver(i)tetra iodo mercurate (iii) <old name New name> silver(i) tetra iodo hydrargirate (iii)

[CoBr(NH₃)₅]SO₄=penta ammine bromo cobalt (iii) sulfate

Will aluminum metal displace Cu²⁺ ion from aqueous solution? That is, will a spontaneous reaction occur in the forward direction for the following reaction?

E⁰_Cu2+/Cu=0.34, E⁰_Al3+/Al=-1.66, E=E_cat-E_an=0.34+1.66=2

dG= -nFE= -6*96500*2=-1.2*10⁶=-1158 kJ <0, so Al displaces Cu²⁺ from the aq.solution

Describe all the properties of the elements Halogen Family

The structure of the atom:

The halogens or halogen elements are a group in the periodic table consisting of five chemically related elements, fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). In the modern IUPAC nomenclature, this group is known as group

They’re diatomic molecules symbolized by X₂. Halogens have 7 valence electrons, which explains why they’re most active with non-metals. Halogen atoms only need to gain 1 electron to fill their outermost energy level. The group of halogens is the only periodic table group which contains elements in all three familiar states of matter at standard temperature and pressure. Halogens are less reactive as you go down the group.

In nature: They’re never found free in nature, only as compounds.

Production:

· Chlorine and fluorine

Electrolysis: 2HF ->H_2(g) + F_2(g)

· Bromine

Seawater is 70ppm Br^-, acidify and oxidize with Cl₂

Cl_2(g) + 2Br^-_(aq) -> 2Cl^- + Br₂

· Iodine

Also obtained from inland brines and certain sea plants

NaIO₃ is found in large deposits in Chile

The physical properties:

	Fluorine (F)	Chlorine (Cl)	Bromine (Br)	Iodine (I)
Physical form At room temp	Pale yellow gas	Yellow-green gas	Dark red liquid	Violet-black solid
M.P ^oC	-220	-101	-7.2
B.P ^oC	-188	-35	58.8
Electron conf	[He]2s^22p^5	[Ne]3s^23p^5	[Ar]3d^104s^24p^5	[Kr]4d^105s^25p^5
E.negativity	4.0	3.0	2.8	2.5
E.affinity,kJ*mol^-1	-328.0	-349.0	-324.6	-295.2

Reactions with water

Fluorine reacts vigorously with water to produce oxygen (O₂) and hydrogen fluoride (HF)

2 F₂(g) + 2 H₂O(l) → O₂(g) + 4 HF(aq)

Chlorine has maximum solubility of ca. 7.1 g Cl₂ per kg of water at ambient temperature (21 °C) Dissolved chlorine reacts to form hydrochloric acid (HCl) and hypochlorous acid, a solution that can be used as a disinfectant or bleach:

Cl₂(g) + H₂O(l) → HCl(aq) + HClO(aq)

Bromine has a solubility of 3.41 g per 100 g of water but it slowly reacts to form hydrogen bromide (HBr) and hypobromous acid (HBrO):

Br₂(g) + H₂O(l) → HBr(aq) + HBrO(aq)

Describe the properties of Zinc

The structure of the atom

E.config: [Ar] 3d¹⁰ 4s² [2, 8, 18, 2], oxidation states=+2,+1,0. Atomic radius=134pm, e-negativity=1.65 (Pauling scale). Zinc is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2.

In nature:

Zinc is found in the Earth's crust, but never as a free element. It is found and extracted in various ores such as smithsonite, zinc spar or zinc carbonate, for some, and the largest producer of zinc ore in the world today is Canada. Zinc is a very common substance that occurs naturally. Many foodstuffs contain certain concentrations of zinc. Drinking water also contains certain amounts of zinc, which may be higher when it is stored in metal tanks. Industrial sources or toxic waste sites may cause the zinc amounts in drinking water to reach levels that can cause health problems.

Production: Roasting converts the zinc sulfide concentrate produced during processing to zinc oxide:

2 ZnS + 3 O₂ → 2 ZnO + 2 SO₂

Electrowinning processing leaches zinc from the ore concentrate by sulfuric acid:

ZnO + H₂SO₄ → ZnSO₄ + H₂O

After this step electrolysis is used to produce zinc metal.

2 ZnSO₄ + 2 H₂O → 2 Zn + 2 H₂SO₄ + O₂

The physical properties: Zinc, also referred to in nonscientific contexts as spelter, is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish. It is somewhat less dense than iron and has a hexagonal crystal structure.The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C. Above 210 °C, the metal becomes brittle again and can be pulverized by beating.Zinc is a fair conductor of electricity.

The chemical properties

Reaction of zinc with air:
Zinc metal tarnishes in moist air. Zinc metal burns in air to form the white zinc(II) oxide, a material that tirns yellow on prolonged heating.
2Zn(s) + O2(g) → 2ZnO(s) [white]
Reaction of zinc with water:
Zinc does not react with water.
Reaction of zinc with the halogens:
Zinc dibromide, zinc(II) dibromide, ZnBr2, and zinc diiodide, zinc(II) dibiodide, NiI2, are formed in the reactions of zinc metal and bromine, Br2, or iodine, I2.

Zn(s) + Br2(g) → ZnBr2(s) [white] Zn(s) + I2(g) → ZnI2(s) [white]

Reaction of zinc with acids:
Zinc metal dissolves slowly in dilute sulphuric acid to form solutions containing the aquated Zn(II) ion together with hydrogen gas, H2. In practice, the Zn(II) is present as the complex ion [Zn(OH2)6]2+.
Zn(s) + H2SO4(aq) → Zn2+(aq) + SO42-(aq) + H2(g)

Transition elements generally are expected to have which of these properties? Explain. Answer: Colored ions in solution

The atom of the metal absorbs light of certain wavelength. This causes electrons to be promoted to a certain energy level. The energy jump here corresponds to the energy of the light that is emitted. In a normal metal atom, the only possible energy jumps are too great for visible light to be affected, and so the solutions appear colourless. However, transition metals are different. When there are ligands present, the 3d level splits up into two levels of energy, with two orbitals at a slightly higher level and three at a lower level. The energy jump when an electron is transferred between two of these levels corresponds to the energy of visible light. This is why the solutions of the ions are coloured.

Describe the properties of Phosphorus

The structure of the atom:

Name: Phosphorus
Symbol: P
Atomic Number: 15
Atomic Mass: 30.97376 amu
Melting Point: 44.1 °C (317.25 K, 111.38 °F)
Boiling Point: 280.0 °C (553.15 K, 536.0 °F)
Number of Protons/Electrons: 15
Number of Neutrons: 16
Classification: Non-metal
Crystal Structure: Monoclinic
Density @ 293 K: 1.82 g/cm³
Color: white

Configuration: [Ne] 3s² 3p³

Number of Energy level: 3

First level: 2 electrons

Second level: 8 electrons

Third level: 5

Isotopes

P-31 Stable

P-32 14.28 days

P-33 24.3 days

In nature

Phosphorus is not found free in nature, but it is widely distributed in many minerals, mainly phosphates. Phosphate rock, which is partially made of apatite (an impure tri-calcium phosphate mineral), is an important commercial source of this element. About 50 percent of the global phosphorus reserves are in the Arab nations. Large deposits of apatite are located in China, Russia, Morocco, Florida, Idaho, Tennessee, Utah, and elsewhere. Albright and Wilson in the United Kingdom and their Niagara Fallsplant, for instance, were using phosphate rock in the 1890s and 1900s from the Îles du Connétable, Tennessee and Florida; by 1950 they were using phosphate rock mainly from Tennessee and North Africa. In the early 1990s Albright and Wilson's purified wet phosphoric acid business was being adversely affected by phosphate rock sales by China and the entry of their long-standing Moroccan phosphate suppliers into the purified wet phosphoric acid business. In 2012, the USGS estimated 71 billion tons of world reserves, where reserve figures refer to the amount assumed recoverable at current market prices; 0.19 billion tons were mined in 2011.

Production

4 Ca₅(PO₄)₃F + 18 SiO₂ + 30 C → 3 P₄ + 30 CO + 18 CaSiO₃ + 2 CaF₂

2 Ca₃(PO₄)₂ + 6 SiO₂ + 10 C → 6CaSiO₃ + 10 CO + P₄

Physical properties

The melting point of phosphorus (white) is 44.1°C, boiling point (white) is 280°C, specific gravity (white) is 1.82, (red) 2.20, (black) 2.25-2.69, with a valence of 3 or 5. There are four allotropic forms of phosphorus: two forms of white (or yellow), red, and black (or violet). White phosphorus exhibits a and b modifications, with a transition temperature between the two forms at -3.8°C. Ordinary phosphorus is a waxy white solid. It is colorless and transparent in its pure form. Phosphorus is insoluble in water, but soluble in carbon disulfide. Phosphorus burns spontaneously in air to its pentoxide. It is highly poisonous, with a lethal dose of ~50 mg. White phosphorus should be stored under water and handled with forceps. It causes severe burns when in contact with skin. White phosphorus is converted to red phosphorus when exposed to sunlight or heated in its own vapor to 250°C. Unlike white phosphorus, red phosphorus does not phosphoresce in air, although it still requires careful handling.

Chemical Properties

White phosphorus is more reactive than red phosphorus. White phosphorus catches fire spontaneously in air, burning to make smoke of phosphorus(V) oxide. If it burns in a little air, it produces poisonous phosphorus(III) oxide. When white phosphorus is heated in an alkali, itdisproportionates to produce hypophosphites and phosphine. Red phosphorus can burn but needs to be ignited. Phosphorus reacts with the halogens to make phosphorus halides. It reacts with some metals to make phosphides.

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