The halogens consist of some of the most reactive elements on the periodic table with the most electronegative element fluorine being the top of the group. All of the molecules in group 7 have a high electron affinity and therefore a high electronegativity.
Fluorine
The comparison of fluorine and chlorine
The electron affinity of chlorine is higher than the electron affinity of chlorine although that’s to say that fluorine has a higher electronegativity. The electron affinity of chlorine is higher because it has less electron shielding compared to a fluorine atom which has a large amount of electrons held very closely to the nucleus.
The reason why fluorine’s electronegativity is higher is that fluorine has very high lattice energy when in an ionic structure and also has a very high covalent bonding attraction.
Fluorine is a very reactive molecule and is only found in its elemental form in extreme natural cases. Otherwise it is normally always found as a compound. Fluorine is prepared through the electrolysis of hydrogen fluoride it is very important that this is anhydrous as a violent reaction will occur if not.
Flouride ions in an aqueous solution forms biflouride (F2H)- this is a molecule that has the strongest hydrogen bonding where the bond is in the region of strength of a covalent bond. Fluorine forms oxygen fluoride this shows how reactive fluorine is when it is the more electronegative element in a compound containing oxygen. This is where the oxygen is present at oxidation state +2.
Fluorine can be stored in copper or steel vessels which form a protective layer of CuF across the inside of the container.
Fluorine forms a mixture of compounds with sulphur the only non-toxic being the relatively inert and dense gas SF6.
The halogens as acids
It is important to note H-F IS NOT A STRONG ACID! IT’S NOT IT’S REALLY NOT ITS LIKE ONLY A LITTLE BIT STRONGER THAN ACETIC ACID!!!!!
Sorry, but you see my point.
The halogens are all able to form acidic compounds on the reaction of them and hydrogen the strength of these acids vary by a pKa of 13 and are all very different in reactivities.
H-F: Contains a good orbital overlap with hydrogen and is not the most effective leaving group, this leaves it to having a pKa of 3.5 which is weak for an acid.
H-Cl: Worse orbital overlap compared to the hydrogen-fluorine bond. This means that is is a better acid that hydrogen fluoride and has a pKa of -7.
H-Br: Stronger acid still at pKa of -9.
H-I: Very weak orbital overlap leaving a very high dissociation constant. This has a pKa of -10.
Fluorine
The comparison of fluorine and chlorine
The electron affinity of chlorine is higher than the electron affinity of chlorine although that’s to say that fluorine has a higher electronegativity. The electron affinity of chlorine is higher because it has less electron shielding compared to a fluorine atom which has a large amount of electrons held very closely to the nucleus.
The reason why fluorine’s electronegativity is higher is that fluorine has very high lattice energy when in an ionic structure and also has a very high covalent bonding attraction.
Fluorine is a very reactive molecule and is only found in its elemental form in extreme natural cases. Otherwise it is normally always found as a compound. Fluorine is prepared through the electrolysis of hydrogen fluoride it is very important that this is anhydrous as a violent reaction will occur if not.
Flouride ions in an aqueous solution forms biflouride (F2H)- this is a molecule that has the strongest hydrogen bonding where the bond is in the region of strength of a covalent bond. Fluorine forms oxygen fluoride this shows how reactive fluorine is when it is the more electronegative element in a compound containing oxygen. This is where the oxygen is present at oxidation state +2.
Fluorine can be stored in copper or steel vessels which form a protective layer of CuF across the inside of the container.
Fluorine forms a mixture of compounds with sulphur the only non-toxic being the relatively inert and dense gas SF6.
The halogens as acids
It is important to note H-F IS NOT A STRONG ACID! IT’S NOT IT’S REALLY NOT ITS LIKE ONLY A LITTLE BIT STRONGER THAN ACETIC ACID!!!!!
Sorry, but you see my point.
The halogens are all able to form acidic compounds on the reaction of them and hydrogen the strength of these acids vary by a pKa of 13 and are all very different in reactivities.
H-F: Contains a good orbital overlap with hydrogen and is not the most effective leaving group, this leaves it to having a pKa of 3.5 which is weak for an acid.
H-Cl: Worse orbital overlap compared to the hydrogen-fluorine bond. This means that is is a better acid that hydrogen fluoride and has a pKa of -7.
H-Br: Stronger acid still at pKa of -9.
H-I: Very weak orbital overlap leaving a very high dissociation constant. This has a pKa of -10.