Zvinhu zveMakemikari zveAlkaline Earth Elements
Zvinhu zvepanyika zvine alkaline iboka rezvinhu zviri mutafura yeperiodic zviri muboka reIIA (boka rechipiri), zvinoti beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), uye radium (Ra). Boka iri rinonzi "alkaline earth" nekuti ma oxides avo ndiwo akakosha (alkaline) uye mumazuva ekutanga ekemikari aiwanzo kuwanikwa mu "earth" minerals (matombo). Kubva pamaonero emakemikari, zvinhu zvepanyika zvine alkaline zvinozivikanwa kuti zvine ma electron maviri e valence saka zvinowanzo gadzira ma ions ane chaji ye +2. Hunhu uhwu hunokosha pakugadziriswa, mhando dzema bond, uye maitiro ekuita zvinhu mumhuri iyi yezvinhu.
1. Magadzirirwo eElectron uye Nhamba dzeOxidation
Kazhinji, zvinhu zvepanyika zvine chimiro chekunze che ns². Izvi zvinoreva kuti zvine maerekitironi maviri e valence mugoko razvo rekunze. Sezvo zvichigadzikana zvakanyanya kana zvikawana chimiro chegasi rakanaka, zvinhu izvi zvinowanzorasikirwa nemaerekitironi maviri kana zvichiita reactive, zvichigadzira M²⁺ cation. Saka, nhamba inonyanya kushandiswa uye yakagadzikana ye oxidation yezvinhu zvepanyika zvine chimiro che +2.
Katsika kekugadzira ma +2 ions kanoita kuti ma alkaline earth compounds ave ma ionic, kunyanya kune zvinhu zvinorema zvakaita seCa, Sr, naBa. Zvisinei, zvinhu zvidiki zvakaita seBe zvine hunhu hwakasiyana; ma compounds avo anowanzova covalent zvakanyanya nekuda kwekugona kwavo kuparadzanisa zvinhu zvakanyanya.
2. Simba reIonization uye Reactivity
Kushanda kwe alkaline earth elements kunowedzera kubva kumusoro kusvika pasi peboka. Izvi zvine chekuita nekuwedzera kweatomic radius uye kudzikira kwesimba reionization. Paunodzika, ma valence electrons ari kure ne nucleus uye anobviswa zviri nyore, saka element yacho inova nyore kuita.
Kurongeka kwakajairika kwemaitiro ekuita reactivity ndekwekuti:
Iva < Mg < Ca < Sr < Ba < Ra
Zvisinei, zvinofanira kucherechedzwa kuti beryllium yakasiyana uye haina simba rekuita zvinhu kupfuura dzimwe nhengo. Haitomboiti zvinhu nekukurumidza nemvura mumamiriro ezvinhu akajairwa nekuti ganda rakatetepa reoxide rinoita kuti ridzivirire pamusoro paro. 3. Kuita Zvinhu Nemvura Chimwe chezvinhu zvinoshamisa zvemakemikari esimbi dzealkaline earth metals kugona kwadzo kuita zvinhu nemvura, kunyangwe zvisiri nekukurumidza sesimbi dzealkali (boka 1). - Be: haiite zvinhu nemvura nekuda kweBeO layer yakagadzikana. - Mg: inoita zvinhu zvishoma nezvishoma nemvura inotonhora, asi inoita zvinhu nekukurumidza nemvura inopisa kana utsi. - Ca, Sr, Ba: inoita zvinhu nemvura inotonhora kuti igadzire hydroxides nehydrogen gas. Mienzaniso yekuita zvinhu: - Kune calcium: Ca(s) + 2H₂O(l) → Ca(OH)₂(aq) + H₂(g) - Kune magnesium ine utsi: Mg(s) + H₂O(g) → MgO(s) + H₂(g) Kuita zvinhu uku kunoratidza kuti simbi dzealkaline earth metals dzakasimba kwazvo, nekuti dzinogona kuderedza mvura kuita hydrogen gas. 4. Kusangana neOxygen neOxide Formation Zvinhu zveAlkaline earth zvinowanzosangana neoxygen kuti zvigadzire ma oxide. Chigadzirwa chikuru chinowanzova simple oxide (MO). Zvisinei, zvinhu zvinorema zvinogonawo kuumba peroxides. - Mg + O₂ → MgO - 2Ca + O₂ → 2CaO (primary) - Ba inowanzo kuumba BaO₂ (peroxide) pasi pemamwe mamiriro: Ba + O₂ → BaO₂ Kusimba kwema oxide kunowedzera kubva kumusoro kusvika pasi. BeO i amphoteric (inogona kuva acidic uye basic), MgO haina simba, nepo CaO, SrO, uye BaO zviri nyore uye zvinosangana nemvura kuti zvigadzire ma hydroxide. 5. Hydroxide Formation uye Basicity Alkaline earth hydroxides ine fomura yakajairika M(OH)₂. Simba rekutanga uye kunyungudika kwema hydroxide kunowedzera kubva kumusoro kusvika pasi peboka: - Be(OH)₂: amphoteric, isinganyungudike zvakanaka. - Mg(OH)₂: hwaro husina kusimba, kunyungudika kwakaderera (kunozivikanwa se "mukaka we magnesia" wemishonga inorwisa maasidhi). - Ca(OH)₂: inonyungudika zvishoma, inozivikanwa se slaked lime. - Sr(OH)₂ na Ba(OH)₂: hwaro hunonyungudika uye hwakasimba. Kuwedzera kwekunyungudika uku kunokonzerwa nekuderera kwesimba re lattice uye shanduko musimba re hydration. Kazhinji, kune hydroxides dzeboka rechipiri, kunyungudika kunowedzera pasi nekuti simba re lattice rinoderera zvakanyanya kupfuura kudzikira kwesimba re hydration. 6. Maitiro neHalogens neHalide Formation Alkaline earth metals inobata nema halogens (F₂, Cl₂, Br₂, I₂) kugadzira ionic halides ne formula MX₂. Mienzaniso: - Mg + Cl₂ → MgCl₂ - Ca + Br₂ → CaBr₂ Alkaline earth halides inowanzova ionic uye ine poindi dzekunyunguduka zvakanyanya. Zvisinei, pane zvimwe zvakakosha: BeCl₂ inonyanya kubatana uye inogona kuumba polymeric structures. Pamusoro pezvo, kunyunguduka kwehalides kunosiyana; semuenzaniso, CaF₂ hainyunguduke zvakanaka nekuda kwesimba rayo rakawanda re lattice. 7. Maitiro neAcids uye Properties seReducing Agent Alkaline earth halides inowanzo sangana neacids kugadzira munyu nehydrogen gas, zvichiratidza basa rayo sereducing agents. Mienzaniso: - Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g) - Ca(s) + H₂SO₄(aq) → CaSO₄(s) + H₂(g) Kuita kwecalcium nesulfuric acid kunogona kunonoka nekuda kwekuumbwa kweCaSO₄ iyo isinganyunguduke zvakanaka. Kazhinji, kana boka rakaderera, ndipo panobva paita kuti acids ikurumidze kusanganiswa nekuti simbi yacho inonyungudika zviri nyore. 8. Kuumbwa kweCarbonate, Sulfate, uye Nitrate Salts Alkaline earth salts ine maitiro ekunyungudika: a) Carbonate (MCO₃) Alkaline earth carbonates inowanzo kuve yakaoma kunyungudika mumvura, kunyanya CaCO₃, SrCO₃, uye BaCO₃. MgCO₃ inonetsawo kunyungudika. CaCO₃ inowanikwa zvakanyanya se limestone, marble, uye calcite. Macarbonate aya anoora kana apiswa: - CaCO₃(s) → CaO(s) + CO₂(g) b) Sulfate (MSO₄) Kunyungudika kwemasulfate kunoderera kubva kumusoro kusvika pasi: - MgSO₄ inonyungudika zvakanaka, - CaSO₄ inonyungudika zvishoma, - BaSO₄ inonyungudika zvishoma (inowanzo shandiswa mu x-ray procedures se contrast medium nekuti yakachengeteka uye hainyungudike). c) Nitrate (M(NO₃)₂) Alkaline earth nitrates inowanzo nyungudika mumvura. Kana yapiswa, aya ma nitrate anowanzo nyungudika kuita ma oxides, nitrogen dioxide, uye oxygen: - 2Ca(NO₃)₂ → 2CaO + 4NO₂ + O₂ 9. Complexes uye Amphoteric Properties yeBeryllium Beryllium ndiyo nhengo inonyanya kutsauka. Nekuda kwehukuru hwayo hudiki uye +2 charge yakakwira, Be²⁺ ine simba guru rekuparadzanisa saka macompounds ayo anowedzera covalent. Be(OH)₂ naBeO zvine amphoteric, zvinokwanisa kuita react nemaacid nemabases ese ari maviri: - Nemaacids: Be(OH)₂ + 2HCl → BeCl₂ + 2H₂O - Nemabases akasimba (anogadzira beryllate complexes): Be(OH)₂ + 2OH⁻ → [Be(OH)₄]²⁻ Hunhu uhwu hwakaoma hunoratidza kuti kemikari yeberyllium yakafanana neyemamwe ma nonmetals pane yemamwe maalkaline earth metals. 10. Mhedziso Hunhu hwemakemikari e alkaline earth elements hunokonzerwa zvakanyanya ne ns² electron configuration yavo inoita kuti ive yakasimba muchimiro che M²⁺ ions. Reactivity inowedzera kubva kuBe kuenda kuBa sezvo simba reionization richiderera. Zvinoita react nemvura, acids, halogens, uye oxygen mune imwe pattern: kugadzira ma oxides, hydroxides, uye ionic salts. Pamusoro pezvo, shanduko mukunyungudika kwemakomputa akadai se hydroxides, carbonates, uye sulfates inoratidza maitiro akakosha enguva nenguva mukuongorora kwemakemikari. Pakati pazvo, beryllium yakasiyana muhunhu hwayo hwe amphoteric uye maitiro ayo akasimba e covalent. Kunzwisisa hunhu hwemakemikari e alkaline earth metals kwakakosha kwete chete mudzidziso yenguva nenguva asiwo mumaindasitiri, zvakatipoteredza, uye mashandisirwo ezuva nezuva - semuenzaniso, mu lime (CaO/Ca(OH)₂), carbonate minerals, Mg(OH)₂ antacids, uye kunyange BaSO₄ mukurapa.