Azotat de magneziu

Acest zvon despre subiectul săruri este doar o schiță . Contribuiți la îmbunătățirea acestuia în conformitate cu convențiile Wikipedia .

Azotat de magneziu
Numele IUPAC
Azotat de magneziu
Caracteristici generale
Formula moleculară sau brută	Mg (NO 3 ) 2 (anhidru) Mg (NO 3 ) 2 2H 2 O (dihidrat) Mg (NO 3 ) 2 6H 2 O (hexahidrat)
Masa moleculară ( u )	148,30 g / mol (anhidru) 184,33 g / mol (dihidrat) 256,41 g / mol (hexahidrat)
Aspect	solid alb cristalin
numar CAS	10377-60-3 (anhidru) 15750-45-5 (dihidrat) 13446-18-9 (hexahidrat)
Numărul EINECS	233-826-7
PubChem	25212
ZÂMBETE	[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[Mg+2]
Proprietăți fizico-chimice
Densitate (g / cm 3 , în cs )	2,3 g / cm3 (anhidru) 2,0256 g / cm3 (dihidrat) 1,464 g / cm3 (hexahidrat)
Indicele de refracție	1,34 (hexahidrat)
Solubilitate în apă	125 g / 100 ml
Temperatură de topire	129 ° C (dihidrat) 88,9 ° C (hexahidrat)
Informații de siguranță
Simboluri de pericol chimic
Expresii R.	R8, R36, R37, R38
Fraze S.	S17, S26, S36
Editați datele pe Wikidata · Manual

Azotatul de magneziu este o sare higroscopică . Este ușor solubil atât în apă, cât și în etanol . Poate exista sub trei forme diferite: ca anhidru, ca dihidrat și ca hexahidrat. Se folosește ca îngrășământ . Apare în mod natural numai în mine și peșteri sub formă de nitromagnezit (formă de hexahidrat). ^[1]

Sinteză

Azotatul de magneziu poate fi obținut în mai multe moduri, dintre care cele mai frecvente sunt reacția redox dintre acidul azotic și magneziul metalic,

${\displaystyle \mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">HNO</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">3</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">+</span></span>\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">Mg</span></span>}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">⟶</span></span>\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">Mg</span></span>}{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">(</span></span>{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">NU</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">3</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">)</span></span>}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">+</span></span>{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">H.</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}^{}}${\ displaystyle {\ ce {2HNO3 + Mg -> Mg (NO3) 2 + H2}}}

reacția dintre acidul azotic și oxidul de magneziu

${\displaystyle \mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">HNO</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">3</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">+</span></span>\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">MgO</span></span>}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">⟶</span></span>\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">Mg</span></span>}{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">(</span></span>{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">NU</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">3</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">)</span></span>}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">+</span></span>{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">H.</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}^{}\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">SAU</span></span>}}${\ displaystyle {\ ce {2HNO3 + MgO -> Mg (NO3) 2 + H2O}}}

și reacția dintre hidroxidul de magneziu și azotatul de amoniu

${\displaystyle \text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">Mg</span></span>}{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">(</span></span>\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">OH</span></span>}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">)</span></span>}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">+</span></span>\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">NH</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">4</span></span>}}^{}{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">NU</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">3</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">⟶</span></span>\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">Mg</span></span>}{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">(</span></span>{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">NU</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">3</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">)</span></span>}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">+</span></span>\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">NH</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">3</span></span>}}^{}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">+</span></span>\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}{\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">H.</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}^{}\text{<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;">SAU</span></span>}}${\ displaystyle {\ ce {Mg (OH) 2 + 2NH4NO3 -> Mg (NO3) 2 + 2NH3 + 2H2O}}}

Reactivitate

Azotatul de magneziu anhidru într-un mediu umed se transformă rapid în hexahidratul corespunzător cu formula Mg (NO ₃ ) ₂ · 6H ₂ O. Azotatul de magneziu hexahidrat dacă este adus la temperatura de 330 ° C nu se topește, dar suferă descompunere:

2Mg (NO ₃ ) ₂ - ^Δ → 2 MgO + 4 NO ₂ + O ₂

Notă

Elemente conexe

• Ciclul azotului

Alte proiecte

• Wikimedia Commons conține imagini sau alte fișiere pe azotat de magneziu

Portalul agriculturii

Portalul chimiei