Aluminum sulfate

Aluminum sulfate ;
Names:	aluminum sulfate; cake alum; filter alum; papermaker's alum; Е520 food additive;
Formula:	Al2(SO4)3 (anhydrous); Al2(SO4)3 · 18H2O (octadecahydrate);
Molar mass:	342.147 g/mol (anhydrous); 666.415 g/mol (octadecahydrate);
Density:	2.710 g/cm3 (anhydrous); 1.69 g/cm3 (octadecahydrate);
Crystal system:	monoclinic (octadecahydrate); α=90°, γ=90°; hexagonal (anhydrous); a=8.032 Å, b=8.032 Å, c=21.36 Åα=90°, β=90°, γ=120°; monoclinic (pentahydrate); a=5.4843 Å, b=10.7958 Å, c=20.8427 Åα=90°, β=96.44°, γ=90°; monoclinic (octahydrate); a=7.37 Å, b=20.008 Å, c=9.624 Åα=90°, β=91.62°, γ=90°; monoclinic (decahydrate); a=12.4207 Å, b=7.2896 Å, c=20.239 Åα=90°, β=97.121°, γ=90°; triclinic (alunogen); a=7.42 Å, b=26.97 Å, c=6.02 Åα=89.57°, β=97.34°, γ=91.53°; monoclinic (aluminite); a=7.44 Å, b=15.583 Å, c=11.7 Åα=90°, β=110.18°, γ=90°; monoclinic (jurbanite); a=8.3965 Å, b=12.479 Å, c=8.1549 Åα=90°, β=101.917°, γ=90°; monoclinic (felsobanyaite); a=13.026 Å, b=10.015 Å, c=11.115 Åα=90°, β=104.34°, γ=90°;
Shapes:	https://en.crystalls.info/w/uploads/media/f/fc/Spherolit.json Spherolit https://en.crystalls.info/w/uploads/media/5/52/Needle.json Needle ;
Color:	white; colorless;
Melting point:	86.5 °C359.65 K <br />187.7 °F <br />647.37 °R <br /> (octadecahydrate);
Decomposition point:	580 °C853.15 K <br />1,076 °F <br />1,535.67 °R <br /> (anhydrous); 150 °C423.15 K <br />302 °F <br />761.67 °R <br /> (octadecahydrate); 160 °C433.15 K <br />320 °F <br />779.67 °R <br /> (tetradecahydrate); 250 °C523.15 K <br />482 °F <br />941.67 °R <br /> (decahydrate); 420 °C693.15 K <br />788 °F <br />1,247.67 °R <br /> (trihydrate);
Refractive index:	1.47 (octadecahydrate);
Magnetic properties:	diamagnetic; χ=-9.30 · 10-5cm³/mol;
Hardness:	fragile; (1.5 on Moh's scale);
Toxicity:	slightly toxic; LD50=980mg/kg

Description

Inorganic compound, salt of transitional metal aluminum and inorganic sulfuric acid From water solutions crystallizes as octadecahydrate.

Minerals

Occurs in nature as alunogen, aluminite, rostite, jurbanite and felsobanyaite minerals.

Precursors

Reaction between aluminum hydroxide and sulfuric acid

Chemical equation:

2Al(OH)₃ + 3H₂SO₄ = Al₂(SO₄)₃ + 6H₂O

For preparation of 100.00g of aluminum sulfate

octadecahydrateoctadecahydrate
anhydrous

а 23.41g of aluminum hydroxide and 119.33g of 37%37% sulfuric acid is required.

Add acid to the flask, then add small parts of aluminum compound with stirring until it will totally dissolve . After reaction will stop, filter the solution and use it for crystal growing.

Reaction between potassium alum, sodium hydroxide and sulfuric acid

Chemical equation:

2KAl(SO₄)₂ + 6NaOH = K₂SO₄ + 3 Na₂SO₄ + 2Al(OH)₃↓

2Al(OH)₃ + 3H₂SO₄ = Al₂(SO₄)₃ + 6H₂O

For preparation of 100.00g of aluminum sulfate

octadecahydrateoctadecahydrate
anhydrous

а 77.49g of aluminum-potassium sulfate and 36.01g of sodium hydroxide or 119.33g of 37%37% sulfuric acid is required.

Add to the flask with alums solution small parts of sodium hydroxide solution and stir. The large amount of poorly soluble precipitate will form. Settle it out and wash it from soluble impurities few times.Add acid to the flask, then add small parts of aluminum compound with stirring until it will totally dissolve . After reaction will stop, filter the solution and use it for crystal growing.

Reaction between metal aluminum and sulfuric acid

Chemical equation:

2Al + 3H₂SO₄ = Al₂(SO₄)₃ + 3H₂↑

For preparation of 100.00g of aluminum sulfate

octadecahydrateoctadecahydrate
anhydrous

а 8.10g of чистый aluminum and 119.33g of 37%37% sulfuric acid is required.

Add diluted acid solution to the flask, then add aluminum pieces, shavings or powder and stir it until gas emission will stop. After reaction will stop, filter the solution and use it for crystal growing.

Temperature	g/`100,00` g water		g/`100,00` g ethylene glycol
Temperature	(anhydrous)	(octadecahydrate)	(anhydrous)
0°C273.15 K <br />32 °F <br />491.67 °R <br />	`31.2`	`86.85`
10°C283.15 K <br />50 °F <br />509.67 °R <br />	`33.5`	`95.8`
20°C293.15 K <br />68 °F <br />527.67 °R <br />	`36.4`	`107.35`	`16.8`
25°C298.15 K <br />77 °F <br />536.67 °R <br />	`38.5`
30°C303.15 K <br />86 °F <br />545.67 °R <br />	`40.4`	`127.6`
40°C313.15 K <br />104 °F <br />563.67 °R <br />	`45.8`	`167.6`
50°C323.15 K <br />122 °F <br />581.67 °R <br />	`52.2`	`201.4`
60°C333.15 K <br />140 °F <br />599.67 °R <br />	`59.2`	`262.6`
70°C343.15 K <br />158 °F <br />617.67 °R <br />		`348.2`
80°C353.15 K <br />176 °F <br />635.67 °R <br />	`73`
90°C363.15 K <br />194 °F <br />653.67 °R <br />	`80.8`
100°C373.15 K <br />212 °F <br />671.67 °R <br />	`89.04`	`1104`

Slightly soluble in ethanol and methanol.

Gallery

Aluminum sulfateYaroslav Zavada, VKontakteYaroslav ZavadaVKontakte
Aluminum sulfateYaroslav Zavada, VKontakteYaroslav ZavadaVKontakte
Saturated solution crystallization while temperature decreases below 50 °CAluminum sulfate, Yaroslav Zavada, VKontakteYaroslav ZavadaVKontakte

Video

Sources

Aluminum compounds
Simple	Aluminum sulfate (Al₂(SO₄)₃) • Aluminum-ammonium sulfate (NH₄Al(SO₄)₂) • Aluminum-potassium sulfate (KAl(SO₄)₂)
Complex	Trioxalatoaluminates

Sulfates
Simple	Aluminum sulfate (Al₂(SO₄)₃) • Ammonium sulfate ((NH₄)₂SO₄) • Calcium sulfate (CaSO₄) • Cadmium sulfate (CdSO₄) • Cerium(III) sulfate (Ce₂(SO₄)₃) • Cerium(IV) sulfate (Ce(SO₄)₂) • Chromium(III) sulfate (Cr₂(SO₄)₃) • Cobalt(II) sulfate (CoSO₄) • Copper(II) sulfate (CuSO₄) • Gadolinium sulfate (Gd₂(SO₄)₃) • Holmium sulfate (Ho₂(SO₄)₃) • Hydrazine sulfate (N₂H₄ · H₂SO₄) • Iron(II) sulfate (FeSO₄) • Iron(III) sulfate (Fe₂(SO₄)₃) • Lanthanum sulfate (La₂(SO₄)₃) • Lithium sulfate (Li₂SO₄) • Magnesium sulfate (MgSO₄) • Manganese(II) sulfate (MnSO₄) • Neodymium sulfate (Nd₂(SO₄)₃) • Nickel sulfate (NiSO₄) • Potassium sulfate (K₂SO₄) • Praseodymium(III) sulfate (Pr₂(SO₄)₃) • Rubidium sulfate (Rb₂SO₄) • Sodium hydrosulfate (NaHSO₄) • Sodium sulfate (Na₂SO₄) • Yttrium sulfate (Gd₂(SO₄)₃) • Zinc sulfate (ZnSO₄)
Alums	Aluminum-ammonium sulfate (NH₄Al(SO₄)₂) • Aluminum-potassium sulfate (KAl(SO₄)₂) • Chromium(III)-ammonium sulfate (NH₄Cr(SO₄)₂) • Chromium(III)-potassium sulfate (KCr(SO₄)₂) • Cobalt(III)-ammonium sulfate (NH₄Co(SO₄)₂) • Indium(III)-potassium sulfate (KIn(SO₄)₂) • Iron(III)-ammonium sulfate (NH₄Fe(SO₄)₂) • Iron(III)-potassium sulfate (KFe(SO₄)₂) • Manganese(III)-ammonium sulfate (NH₄Mn(SO₄)₂) • Vanadium(III)-ammonium sulfate (NH₄V(SO₄)₂)
Tutton's salts	Chromium(II)-ammonium sulfate ((NH₄)₂Cr(SO₄)₂) • Cobalt(II)-ammonium sulfate ((NH₄)₂Co(SO₄)₂) • Cobalt(II)-potassium sulfate (K₂Co(SO₄)₂) • Copper(II)-ammonium sulfate ((NH₄)₂Cu(SO₄)₂) • Copper(II)-potassium sulfate (K₂Cu(SO₄)₂) • Iron(II)-ammonium sulfate ((NH₄)₂Fe(SO₄)₂) • Iron(II)-potassium sulfate (K₂Fe(SO₄)₂) • Magnesium-ammonium sulfate ((NH₄)₂Mg(SO₄)₂) • Magnesium-potassium sulfate (K₂Mg(SO₄)₂) • Magnesium-potassium sulfate-chromate (K₂CrO₄ · MgSO₄) • Manganese(II)-ammonium sulfate ((NH₄)₂Mn(SO₄)₂) • Manganese(II)-potassium sulfate (K₂Mn(SO₄)₂) • Nickel-ammonium sulfate ((NH₄)₂Ni(SO₄)₂) • Nickel-potassium sulfate (K₂Ni(SO₄)₂) • Vanadium(II)-ammonium sulfate ((NH₄)₂V(SO₄)₂) • Zinc-ammonium sulfate ((NH₄)₂Zn(SO₄)₂) • Zinc-potassium sulfate (K₂Zn(SO₄)₂)
Double salts	Copper(II)-iron(II) sulfate ((Cu,Fe)SO₄) • Iron(II)-magnesium sulfate ((Fe,Mg)SO₄) • Lithium-potassium sulfate (KLiSO₄) • Sodium-ammonium sulfate (NaNH₄SO₄) • Zinc-sodium sulfate (Na₂Zn(SO₄)₂)
Adducts	Triglycine sulfate ((NH₂CH₂COOH)₃ · H₂SO₄) • Glutamic acid sulfate (C₅H₉NO₄ · H₂SO₄)
Complexes	Cerium(III) sulfocerate(IV) (Ce₄[Ce(SO₄)₄]₃) • Glycinecopper(II) sulfate ([Cu(NH₂CH₂COOH)]SO₄) • Hexakarbamatzinc sulfate ([(CON₂H₄)₆Zn]SO₄) • Tetraamminecopper(II) sulfate ([Cu(NH₃)₄]SO₄) • Tris(hydroxymethil)methanoaminecopper(II) sulfate ([Cu(NH₂C(CH₂OH)₃)₄]SO₄)

Aluminum sulfate
Names:	aluminum sulfate cake alum filter alum papermaker's alum Е520 food additive
Formula:	Al₂(SO₄)₃ (anhydrous) Al₂(SO₄)₃ · 18H₂O (octadecahydrate)
Molar mass:	342.147 g/mol (anhydrous) 666.415 g/mol (octadecahydrate)
Density:	2.710 g/cm³ (anhydrous) 1.69 g/cm³ (octadecahydrate)
Crystal system:	monoclinic (octadecahydrate) α=90°, γ=90° hexagonal (anhydrous) a=8.032 Å, b=8.032 Å, c=21.36 Åα=90°, β=90°, γ=120° monoclinic (pentahydrate) a=5.4843 Å, b=10.7958 Å, c=20.8427 Åα=90°, β=96.44°, γ=90° monoclinic (octahydrate) a=7.37 Å, b=20.008 Å, c=9.624 Åα=90°, β=91.62°, γ=90° monoclinic (decahydrate) a=12.4207 Å, b=7.2896 Å, c=20.239 Åα=90°, β=97.121°, γ=90° triclinic (alunogen) a=7.42 Å, b=26.97 Å, c=6.02 Åα=89.57°, β=97.34°, γ=91.53° monoclinic (aluminite) a=7.44 Å, b=15.583 Å, c=11.7 Åα=90°, β=110.18°, γ=90° monoclinic (jurbanite) a=8.3965 Å, b=12.479 Å, c=8.1549 Åα=90°, β=101.917°, γ=90° monoclinic (felsobanyaite) a=13.026 Å, b=10.015 Å, c=11.115 Åα=90°, β=104.34°, γ=90°
Shapes:	Spherolit Needle
Color:	white colorless
Melting point:	86.5 °C359.65 K <br />187.7 °F <br />647.37 °R <br /> (octadecahydrate)
Decomposition point:	580 °C853.15 K <br />1,076 °F <br />1,535.67 °R <br /> (anhydrous) 150 °C423.15 K <br />302 °F <br />761.67 °R <br /> (octadecahydrate) 160 °C433.15 K <br />320 °F <br />779.67 °R <br /> (tetradecahydrate) 250 °C523.15 K <br />482 °F <br />941.67 °R <br /> (decahydrate) 420 °C693.15 K <br />788 °F <br />1,247.67 °R <br /> (trihydrate)
Refractive index:	1.47 (octadecahydrate)
Magnetic properties:	diamagnetic χ=-9.30 · 10^-5cm³/mol
Hardness:	fragile (1.5 on Moh's scale)
Toxicity:	slightly toxic LD₅₀=980mg/kg

Aluminum sulfate

Description

Minerals

Precursors

Reaction between aluminum hydroxide and sulfuric acid

Reaction between potassium alum, sodium hydroxide and sulfuric acid

Reaction between metal aluminum and sulfuric acid

Influence of pH level

Storage conditions

Solubility

Gallery

Video

Sources

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