Name: halogens: trends and reactions
Uploaded: 2020-09-03T13:38:28.000Z
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Halogens

Halogenen zijn een groep van vijf niet-metalen elementen fluor, chloor, broom, jodium en astaat die tot groep 17 behoren. Elementaire halogenen bestaan als twee atomen moleculen. Bij kamertemperatuur zijn fluor en chloor gassen, is broom een vloeistof en is jodium een vaste stof.Er is minder bekend over de eigenschappen van het vijfde element, astaat, een zeldzame en zeer radioactieve vaste stof. De fysieke eigenschappen van halogenen, zoals elementaire kleur, variëren naar beneden in de groep. Atoomstralen nemen toe met toenemend atoomnummer, en het smeltpunt en kookpunt vertonen een stijgende trend van fluor naar jodium.Daarentegen nemen periodieke eigenschappen zoals elektronegativiteit, reactiviteit en elektronenaffiniteit af verder naar beneden in de groep. Elektronenconfiguraties van halogenen geven aan dat ze zeven valentie-elektronen hebben en dat ze één elektron te kort zijn om hun dichtstbijzijnde edelgasconfiguraties te bereiken. Daarom vertonen halogenen hoge elektronegativiteiten met een sterke neiging om één extra elektron te krijgen om hun octet te voltooien, waardoor ze zeer reactieve en krachtige oxidatiemiddelen zijn, vergeleken met andere groepen.Fluor is het krachtigste oxidatiemiddel onder halogenen en jodium het minst. Halogenen vertonen ook zeer negatieve elektronenaffiniteiten, wat de verandering in energie is wanneer een elektron wordt gewonnen door een neutraal atoom. Het wordt uitgedrukt in kilojoules per mol en de negatieve waarde geeft de exotherme aard van de reactie aan.Halogenen reageren met de meeste metalen om metaalhalogeniden te geven. Chloor en natrium reageren bijvoorbeeld om natriumchloride te produceren, een ionische verbinding. Halogenen reageren met waterstof om polaire covalente verbindingen te vormen, waterstofhalogeniden genaamd, die vaak oplossen in water om halogeenwaterstofzuren te vormen.Halogenen reageren ook met water. De reactie van fluor met water is sterk exotherm, waardoor waterstoffluoride een sterk zuur en zuurstof ontstaat. Chloor reageert echter langzamer en produceert zoutzuur en hypochloorzuur een sterk oxidatiemiddel.Bovendien kunnen halogenen met elkaar reageren en binaire, covalente verbindingen produceren die interhalogeenverbindingen worden genoemd. Zo reageert broom met fluor en vormt broomtrifluoride.

halogenen

Groep 17-elementen, bekend als halogenen, zijn niet-metalen. Bij kamertemperatuur zijn fluor en chloor gassen, broom een vloeistof en jodium een vaste stof. Astatine is een zeer onstabiel radioactief element, dus momenteel zijn de meeste eigenschappen ervan onbekend vanwege de korte halfwaardetijd. Tennessine is een synthetisch element dat naar verwachting ook in deze groep voorkomt. De halogenen worden niet als afzonderlijke atomen aangetroffen, maar bestaan als tweeatomige moleculen. De atoomstraal neemt toe van fluor naar jodium. De valentieschil-elektronenconfiguratie van halogenen is ns2np5, en ze hebben de neiging een elektron te accepteren om de edelgasconfiguratie te bereiken. De verschillende eigenschappen van halogenen staan vermeld in tabel 1. Tabel 1: Eigenschappen van de halogenen. <table style="margin-left: auto; margin-right: auto;"> <tbody style="border: 1px solid black;"> <tr> <td style="color: black; border: 1px solid black; text-align: center;">Element</td> <td style="color: black; border: 1px solid black; text-align: center;">Electron Configuration</td> <td style="color: black; border: 1px solid black; text-align: center;">Atomic Radius (pm)</td> <td style="color: black; border: 1px solid black; text-align: center;">IE1 (kJ/mol)</td> <td style="color: black; border: 1px solid black; text-align: center;">EA (kJ/mol)</td> <td style="color: black; border: 1px solid black; text-align: center;">Density at 25 °C </td> <td style="color: black; border: 1px solid black; text-align: center;">Melting Point (°C)</td> </tr> <tr> <td style="color: black; border: 1px solid black; text-align: center;">F</td> <td style="color: black; border: 1px solid black; text-align: center;">[He] 2s22p5</td> <td style="color: black; border: 1px solid black; text-align: center;">71</td> <td style="color: black; border: 1px solid black; text-align: center;">1680</td> <td style="color: black; border: 1px solid black; text-align: center;">-328</td> <td style="color: black; border: 1px solid black; text-align: center;">1.70 g/L</td> <td style="color: black; border: 1px solid black; text-align: center;">-219</td> </tr> <tr> <td style="color: black; border: 1px solid black; text-align: center;">Cl</td> <td style="color: black; border: 1px solid black; text-align: center;">[Ne] 3s23p5</td> <td style="color: black; border: 1px solid black; text-align: center;">99</td> <td style="color: black; border: 1px solid black; text-align: center;">1250</td> <td style="color: black; border: 1px solid black; text-align: center;">-348</td> <td style="color: black; border: 1px solid black; text-align: center;">3.12 g/L</td> <td style="color: black; border: 1px solid black; text-align: center;">-101</td> </tr> <tr> <td style="color: black; border: 1px solid black; text-align: center;">Br</td> <td style="color: black; border: 1px solid black; text-align: center;">[Ar] 4s24p5</td> <td style="color: black; border: 1px solid black; text-align: center;">114</td> <td style="color: black; border: 1px solid black; text-align: center;">1140</td> <td style="color: black; border: 1px solid black; text-align: center;">-324</td> <td style="color: black; border: 1px solid black; text-align: center;">3.19 g/cm3</td> <td style="color: black; border: 1px solid black; text-align: center;">-7</td> </tr> <tr> <td style="color: black; border: 1px solid black; text-align: center;">I</td> <td style="color: black; border: 1px solid black; text-align: center;">[Kr] 5s25p5</td> <td style="color: black; border: 1px solid black; text-align: center;">133</td> <td style="color: black; border: 1px solid black; text-align: center;">1010</td> <td style="color: black; border: 1px solid black; text-align: center;">-295</td> <td style="color: black; border: 1px solid black; text-align: center;">3.96 g/cm3</td> <td style="color: black; border: 1px solid black; text-align: center;">114</td> </tr> </tbody> </table> De elektronenaffiniteiten van halogenen hebben grote negatieve waarden; de halogenen zijn dus krachtige oxidatiemiddelen. Fluor is het krachtigste oxidatiemiddel van de groep met de meeste negatieve elektronenaffiniteit. De halogenen reageren met metalen om het elektron te verkrijgen en het overeenkomstige metaalhalogenide te produceren. Chloor reageert bijvoorbeeld met ijzer om ijzerchloride te geven en met natrium om natriumchloride te geven. De halogenen reageren met waterstof om waterstofhalogeniden te vormen, die in water oplossen en waterstofhalogeenzuren produceren. Fluorwaterstofzuur is het zwakste halozuur. Fluor reageert krachtig met water. De reactie is zeer exotherm en produceert zuurstof. De reactie van chloor is minder krachtig met water. Het hypochloorzuur dat bij deze reactie wordt geproduceerd, is een sterk oxidatiemiddel. De halogenen reageren met elkaar om interhalogeenverbindingen te vormen, waarvan er vele binaire verbindingen zijn. De algemene molecuulformule voor interhalogeenverbindingen is ABn, waarbij A het halogeen is met een hoger atoomnummer en een oneven getal is. Enkele voorbeelden van interhalogeenverbindingen zijn ICl, IBr, BrF, BrCl, ClF. De halogenen reageren met koolstof en vormen commercieel belangrijke verbindingen. Ethyleen reageert bijvoorbeeld met fluor en geeft perfluorethyleen. Deze tekst is aangepast van <a href="https://openstax.org/books/chemistry-2e/pages/6-5-periodic-variations-in-element-properties">Openstax, Chemistry 2e, Sectie 6.5: Periodieke Variaties in Elementeigenschappen.</a>

Halogenen

Group 17 elements, known as halogens, are nonmetals. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine a solid. ...

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halogens: trends and reactions

Halogens are Group 17 nonmetals that show clear trends in structure and reactivity. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine is a solid. Astatine is highly unstable and radioactive, so most of its properties are still unknown because it has a very short half-life. Tennessine is a synthetic element that is also predicted to belong to this group.

These elements do not usually exist as single atoms. Instead, they form diatomic molecules, which means each molecule has two atoms. Their atomic radius increases from fluorine to iodine, and their outer-shell electron pattern is ns2 np5. This electron arrangement helps explain why halogens tend to gain one electron and reach a noble gas configuration.

The table of halogen properties shows important changes across the group. Fluorine has the smallest atomic radius, while iodine has the largest. First ionization energy decreases from fluorine to iodine, and electron affinity stays strongly negative for the group. Because of this, halogens are powerful oxidizing agents, and fluorine is the strongest oxidizing agent in the group.

Halogens react with metals to form metal halides. For example, chlorine reacts with iron to make iron chloride, and it reacts with sodium to make sodium chloride. They also react with hydrogen to form hydrogen halides. When these dissolve in water, they produce hydrohalic acids, and hydrofluoric acid is the weakest haloacid.

Halogens also react with water, but not in the same way. Fluorine reacts very vigorously, and the reaction is highly exothermic, which means it releases a large amount of heat. It also produces oxygen. Chlorine reacts less vigorously with water, and the hypochlorous acid formed is a strong oxidizing agent.

Halogens can react with one another to form interhalogen compounds, which are often binary compounds. Their general formula is ABn, where A is the halogen with the higher atomic number and n is an odd number. Examples include ICl, IBr, BrF, BrCl, and ClF. Halogens also react with carbon to form useful compounds, such as perfluoroethylene from the reaction of ethylene with fluorine.

Halogens: Trends and Reactions

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Electron Affinity Trends on the Periodic Table

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halogens

Halogens are Group 17 nonmetals that show clear trends in structure and reactivity. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine is a solid. Astatine is highly unstable and radioactive, so most of its properties are still unknown because it has a very short half-life. Tennessine is a synthetic element that is also predicted to belong to this group. These elements do not usually exist as single atoms. Instead, they form diatomic molecules, which means...

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Explore halogen trends, from physical states and electron configuration to oxidizing strength, metal halides, hydrohalic acids, and interhalogen compounds.

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Construct an explanation to classify the type of chemical bond that occurs (covalent, ionic, or metallic) in a given substance.

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Nomenclature of Alkanes

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Understand types, properties, and structure of matter.

Halogens: Trends and Reactions

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