Ammonium dihydrophosphate

Ammonium dihydrophosphate ;
Names:	ammonium dihydrogen phosphate; monoammonium phosphate; ADP; MAP;
Formula:	NH4H2PO4;
Molar mass:	115.025 g/mol;
Density:	1.8 g/cm3;
Crystal system:	tetragonal; a=7.4997 Å, b=7.4997 Å, c=7.5493 Åα=90°, β=90°, γ=90°;
Shapes:	https://en.crystalls.info/w/uploads/media/2/28/Prolongated_tetragonal_pyramidal_prism.json Prolongated tetragonal pyramidal prism https://en.crystalls.info/w/uploads/media/5/50/Beveled_tetragonal_prism.json Beveled tetragonal prism https://en.crystalls.info/w/uploads/media/5/52/Needle.json Needle ;
Color:	colorless;
Melting point:	190 °C463.15 K <br />374 °F <br />833.67 °R <br />;
Decomposition point:	250 °C523.15 K <br />482 °F <br />941.67 °R <br />;
Refractive index:	1.525 ;
Optical properties:	birefringence;
Electricity properties:	piezoelectric; ferroelectric; dielectric;
Stability:	stable;
Hardness:	relatively strong; (2 on Moh's scale);
Toxicity:	non-toxic; LD50=5750mg/kg

Description

Inorganic compound, acid salt of ammonium ion and inorganic phosphoric acid. Doesn't form water hydrates.

Minerals

Occurs in nature as biphosphammite and archerite minerals.

Where to buy

Can be bought in fertilizers store (as "ammophos").

Precursors

Reaction between ammonia and phosphoric acid

Chemical equation:

NH₄OH + H₃PO₄ = NH₄H₂PO₄ + H₂O

For preparation of 100.00g of ammonium dihydrophosphate а 121.87g of

25%25%
10%

ammonia and 100.23g of 85%85% phosphoric acid is required.

Add hot acid to the flask, then add small parts of ammonium compound with stirring until heating will stop (attention, the solution may boil!) . After reaction will stop, filter the solution and use it for crystal growing.

Influence of impurities

Small addition of baking soda or ammonia improves crystal form and transparency.

Influence of pH level

Sharp or needle crystals are forming at lower pH.

Storage conditions

Store in its original form or under several layers of varnish at average humidity and room temperature. Do not store in matchboxes or cotton wool and do not heat.

Solubility

TableGraph

Temperature	гр/`100,00` гр water
0°C273.15 K <br />32 °F <br />491.67 °R <br />	`22.6`
10°C283.15 K <br />50 °F <br />509.67 °R <br />	`28`
20°C293.15 K <br />68 °F <br />527.67 °R <br />	`35.3`
25°C298.15 K <br />77 °F <br />536.67 °R <br />	`39.5`
30°C303.15 K <br />86 °F <br />545.67 °R <br />	`43.9`
40°C313.15 K <br />104 °F <br />563.67 °R <br />	`56.7`
60°C333.15 K <br />140 °F <br />599.67 °R <br />	`82.5`
80°C353.15 K <br />176 °F <br />635.67 °R <br />	`118.3`
100°C373.15 K <br />212 °F <br />671.67 °R <br />	`173.2`

Soluble in ethanol. Insoluble in acetone.

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Ammonium compounds
Salts	Ammonium citrate ((NH₄)₃C₃H₅O(COO)₃) • Ammonium chloride (NH₄Cl) • Ammonium dichromate ((NH₄)₂Cr₂O₇) • Ammonium dihydrophosphate (NH₄H₂PO₄) • Ammonium nitrate (NH₄NO₃) • Ammonium perrhenate (NH₄ReO₄) • Ammonium sulfate ((NH₄)₂SO₄) • Ammonium succinate ((NH₄)₂C₄H₄O₄) • Ammonium tetraborate ((NH₄)₂B₄O₇) • Ammonium thiocyanate (NH₄NCS)
Double salts	Aluminum-ammonium sulfate (NH₄Al(SO₄)₂) • Calcium-ammonium nitrate (5Ca(NO₃)₂ · NH₄NO₃) • Chromium(II)-ammonium sulfate ((NH₄)₂Cr(SO₄)₂) • Chromium(III)-ammonium sulfate (NH₄Cr(SO₄)₂) • Cobalt(II)-ammonium sulfate ((NH₄)₂Co(SO₄)₂) • Cobalt(III)-ammonium sulfate (NH₄Co(SO₄)₂) • Copper(II)-ammonium sulfate ((NH₄)₂Cu(SO₄)₂) • Iron(II)-ammonium sulfate ((NH₄)₂Fe(SO₄)₂) • Iron(III)-ammonium sulfate (NH₄Fe(SO₄)₂) • Magnesium-ammonium sulfate ((NH₄)₂Mg(SO₄)₂) • Manganese(II)-ammonium sulfate ((NH₄)₂Mn(SO₄)₂) • Manganese(III)-ammonium sulfate (NH₄Mn(SO₄)₂) • Nickel-ammonium sulfate ((NH₄)₂Ni(SO₄)₂) • Sodium-ammonium sulfate (NaNH₄SO₄) • Vanadium(II)-ammonium sulfate ((NH₄)₂V(SO₄)₂) • Vanadium(III)-ammonium sulfate (NH₄V(SO₄)₂) • Zinc-ammonium sulfate ((NH₄)₂Zn(SO₄)₂)
Complexes	Ammines • Ammonium dioxalatocuprate(II) ((NH₄)₂[Cu(C₂O₄)₂]) • Ammonium pentachloroferrate(III) ((NH₄)₂[FeCl₅]) • Ammonium tetrachlorocuprate(II) ((NH₄)₂[CuCl₄]) • Ammonium trioxalatoferrate(III) ((NH₄)₃[Fe(C₂O₄)₃])

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)

Ammonium dihydrophosphate
Names:	ammonium dihydrogen phosphate monoammonium phosphate ADP MAP
Formula:	NH₄H₂PO₄
Molar mass:	115.025 g/mol
Density:	1.8 g/cm³
Crystal system:	tetragonal a=7.4997 Å, b=7.4997 Å, c=7.5493 Åα=90°, β=90°, γ=90°
Shapes:	Prolongated tetragonal pyramidal prism Beveled tetragonal prism Needle
Color:	colorless
Melting point:	190 °C463.15 K <br />374 °F <br />833.67 °R <br />
Decomposition point:	250 °C523.15 K <br />482 °F <br />941.67 °R <br />
Refractive index:	1.525
Optical properties:	birefringence
Electricity properties:	piezoelectric ferroelectric dielectric
Stability:	stable
Hardness:	relatively strong (2 on Moh's scale)
Toxicity:	non-toxic LD₅₀=5750mg/kg