Chemical of the Day - Fluorine

I didn't really want to do this chemical / element cus it's too bitchy. Yes take that fluorine is a bitch.
The thing about fluorine is that although it is in the same group as chlorine and friends, its chemical behaviour is the very extreme big brother type.
Simply put, spray a puff of fluorine on almost anything and it will burst into flames.
Never mind, moving on to more important things about fluorine, apart from how much of a bitch it is of course.
Name: Fluorine (teh bitch)
Formula: F2 (exists as diatomic molecule)
Phase at room temperature: Pale yellow gas (almost colourless unless concentrated)
Oxidation states: 0 (as F2), -1 (as everything else)

Reactions: something wonderful known as oxidising anything that it dislikes (which is basically almost anything)
Anyways, fluorine, being the most electronegative element of the periodic table based on one type of definition, is able to oxidise many objects. Fluorine in the form of F2 is very reactive due to its weak F-F bond, and of course its high tendency to gain 1 electron from other compounds to attain F-.

Inorganic:
Reaction between fluorine and an element usually brings its oxidation number to the highest number.
Fluorine is able to form ionic fluoride with all metals (except beryllium which is an equal bitch)
Solubility of metal fluorides are generally different from solubility of its respective chlorides and and bromides. (except for group 1 salts, since they are all soluble.)
For example, group 2 fluorides are generally insoluble, while their respective chlorides and bromides are all soluble. (As a matter of fact calcium chloride is so soluble that it absorbs moisture from the air)
Silver fluoride is soluble. (compare with silver chloride and the rest)
As number of fluorides present increases, solubility decreases.
While metal trifluorides and below are ionic solids, metal pentafluorides and above are volatile molecules. Metal tetrafluorides is the borderline, as ZrF4 is an ionic solid while GeF4 is a gas.
Gaseous fluorine can basically displace any less electronegative element which is the more electronegative element bonded to a compound. For example it displaces oxygen from water to form HF and O2.
It can react with noble gases below neon to form stable compounds. Examples are XeF4, HArF, RnF2.

Organic:
The main organic thing about fluorine is that it forms the strongest covalent bond in organic chemistry, ie the C-F bond. It is able to replace the hydrogen in hydrocarbons even at room temperature, forming C-F bonds as long as there is enough hydrogen / fluorine.
Other than that there's not much interesting things fluorine can do to organic compounds. I mean like it only rapes away hydrogen and more hydrogen. Oh, one of its compound, polyfluoroethene aka teflon, is the only material that a gecko cannot stick to. No prize at guessing what's it used for.

Uses:
Used as a fluorinating agent (surprise!) to produce other fluorine containing compounds, which are usually useful, such as hydrofluoric acid, teflon and other substances used as protective materials, because usually a fluorine something bond is very stable.

Other stuff:
Fluorine has noob F-F bond due to small size of atom resulting in repulsion between the atoms, causing the bond to be weaker as compared to say Cl-Cl.
Fluorine is the 13th most abundant element on earth! How lucky!
Fluorine has the highest first IE barring the other 2 noble gases.

Ok now gc will talk about random dota trivia. (wut)

Chemical of the Day - Potassium Manganate (VII)

Somehow gc likes easy chemicals o.o maybe we start with easy stuff and move to hardcore mugging later. Potassium manganate (VII) or potassium permanganate is interesting in the sense that the manganese is existing as +7 charge in the compound, which is quite rare even among transition metals, since the maximum oxidation number that an element can exhibit is +8 (which is super rare because most elements will not tend to lose all its 8 electrons)
And seeing that the Mn lost so many electrons, it is quite expected that it would want to gain back some electrons when undergoing chemical reactions. Hence KMnO4 is a strong oxidising agent.


Formula: KMnO4


Appearance: Purple-gray crystals. Purple to magenta solution.
Structure: Giant ionic lattice


Solubility: 6.38g / 100 ml (noober than phenol rofl)


Preparation: (you need a pikachu electricity to do this)
First MnO2 is fused with KOH and heated with a source of oxygen, such as KNO3 or KClO3. This gives K2MnO4 as the product. After which electrolytic oxidation in an alkaline medium would produce KMnO4.
2 MnO₂ + 4 KOH + O₂ → 2 K₂MnO₄ + 2 H₂O
2 MnO₄^2– + Cl₂ → 2 MnO₄^– + 2 Cl^–


Uses:
Inorganic: Used as a standard solution for redox titration in quantitative analysis of reducing agent, such as finding out how much or how concentrated a solution of ascorbic acid is. In this case KMnO4 can undergo 2 types of reduction, first in an acidic medium and second in a non-acidic medium.
In acidic medium:
MnO4- + 8H+ + 5e- -> Mn2+ + 4H2O
In non-acidic medium:
MnO4- + 2H2O + 3e- -> MnO2 + 4OH-
Hence in acidic medium the purple colour will fade to very pale pink (almost colourless), while in non-acidic medium the purple colour will turn to a brown precipitate.


Organic: Used as an oxidising agent to oxidise many organic compounds.
Dilute solution of KMnO4 can oxidise alkenes to diols.
Acidic solution of KMnO4 can cleave (切) C=C bond to form either CO2 & H2O, carboxylic acid or ketone.
CH₃(CH₂)₁₇CH=CH₂ + 2 KMnO₄ + 3 H₂SO₄ → CH₃(CH₂)₁₇COOH + CO₂ + 4 H₂O + K₂SO₄ + 2 MnSO₄
It can oxidise aldehyde to carboxylic acid.
5 C₆H₁₃CHO + 2 KMnO₄ + 3 H₂SO₄ → 5 C₆H₁₃COOH + 3 H₂O + K₂SO₄ + 2 MnSO₄
It can even oxidise alkyl groups on a benzene ring. For example it oxidises toluene to benzoic acid.
5 C₆H₅CH₃ + 6 KMnO₄ + 9 H₂SO₄ → 5 C₆H₅COOH + 14 H₂O + 2 K₂SO₄ + 6 MnSO₄

Other stuff:
It can be used as an antiseptic and disinfectant due to its oxidising nature. (Hence you can buy it from Guardian in dilute solutions meant for treating cuts and stuff)
Reaction of solild KMnO4 with pure glycerol or simple alcohols result in violent combustion.
Reaction with conc H2SO4 produces Mn2O7, which (unsurprisingly) explodes due to instability.
Can rapidly stain any organic material, thought it can be cleaned by washing with a reducing agent (such as ascorbic acid)
Used in banana shipments to absorb the ethene produced by ripening bananas to lengthen their ripening time (wow).

Ok now gc can go and do cyclohexane.

Chemical of the Day - Copper iodide

Ok I shall start off with the chemical of the day then.
So today's chemical is copper (I) iodide.
Some may wonder why it is not copper (II) iodide which is usually the preferred oxidation state for copper.
Nvm wikipedia says nothing about why copper (I) iodide is more stable than copper (II) iodide. My guess would be due to steric strain between the iodide ion and copper ion, since iodine is much larger, so the ionic lattice would be strained.

Formula: CuI

Appearance: white powder (pure). brownish (impure)

Structure: Giant ionic lattice

Ksp: 1 x 10^-12

Preparation: Heating of iodine and copper in concentrated HI,
Addition of KI to a soluble copper salt such as CuSO4. The product formed is CuI2, which decomposes immediately to CuI and I2.
Hence if given an unknown X, which is mixed with KI and then CCl4 is added, if a purple layer is seen with a white powder, it can be quite confirmed that X contains Cu2+, since CuI2 decomposes immediately to give CuI (white powder) and I2 (dissolves to give purple colour in CCl4)

Uses: Organometallic coupling. CuI is one of the reagents required for the synthesis of the Gilman reagent. What this reagent can do is to replace the halide group on a haloalkane with another R group. It is prepared by reaction of an organolithium compound with CuI with diethyl ether as solvent.
2CH3Li + CuI -> (CH3)2CuLi + LiI
In this case the (CH3)2CuLi is the Gilman reagent. Of course the R group bonded to the copper can be changed to other substituent other than methyl group. Gilman reagent can react with haloalkanes as follows:
(CH3)2CuLi + CH3(CH2)8CH2I -> CH3(CH2)8CH2CH3 + LiI + CH3Cu
As can be seen from the reaction, one of the CH3 groups in the Gilman reagent substituted the I from the haloalkane forming a larger alkane as the main product. This reaction is useful as it forms a C-C bond, thereby making possible preparation of larger molecules from smaller ones. This is even more useful as you can use this reaction to add alkyl groups to a benzene compound as well.
C6H5I (iodobenzene) + (CH3)2CuLi -> C6H5CH3 (toluene) + CH3Cu + LiI.

Other info: Used for cloud seeding. Used to detect Hg, upon addition of CuI to Hg, copper tetraiodomercurate is formed which turns the white powder brown. Soluble in concentrated KI to give [CuI2]-

Now gc can go and do phenol. lol.