Ammonium tetraborate | |
---|---|
Names: | ammonium tetraborate ammonium borax
|
Formula: | (NH4)2B4O7 (anhydrous) (NH4)2B4O7 · 4H2O (tetrahydrate) |
SMILES: | B(O)(O)O.B(O)(O)O.B(O)(O)O.B(O)([O-])[O-].[NH4+].[NH4+] |
Molar mass: | 191.315 g/mol (anhydrous) 263.374 g/mol (tetrahydrate) |
Density: | 1.58 g/cm3 (anhydrous) 2.37 g/cm3 (tetrahydrate) |
Crystal system: | tetragonal (tetrahydrate) α=90°, β=90°, γ=90° |
Shapes: | |
Color: | colorless |
Decomposition point: | 87 °C360.15 K <br />188.6 °F <br />648.27 °R <br /> (tetrahydrate) |
Magnetic properties: | diamagnetic |
Stability: | stable (tetrahydrate) |
Hardness: | relatively strong |
Toxicity: | non-toxic LD50=4200mg/kg |
Description
Inorganic compound, salt of ammonium ion and inorganic tetraboric acid. From water solutions crystallizes as tetrahydrate.
Precursors
Reaction between ammonia and boric acid
Chemical equation:
100.00
g of ammonium tetraborate tetrahydrate
а 106.45
g of 25%
ammonia and 93.91
g of boric 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 temperature
Very slow crystallization and low transparency at room temperature, but growing from hot solution eliminates these drawbacks.
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
Temperature | гр/100,00 гр water | |
---|---|---|
(anhydrous) | (tetrahydrate) | |
0°C273.15 K <br />32 °F <br />491.67 °R <br /> | 3.75 | ~5.2 |
10°C283.15 K <br />50 °F <br />509.67 °R <br /> | ~3.9 | 5.3 |
15°C288.15 K <br />59 °F <br />518.67 °R <br /> | ~4.60 | ~6.29 |
20°C293.15 K <br />68 °F <br />527.67 °R <br /> | ~5.3 | 7.27 |
25°C298.15 K <br />77 °F <br />536.67 °R <br /> | 9 | ~12.5 |
30°C303.15 K <br />86 °F <br />545.67 °R <br /> | ~11.4 | ~15.8 |
40°C313.15 K <br />104 °F <br />563.67 °R <br /> | ~16.3 | ~22.5 |
50°C323.15 K <br />122 °F <br />581.67 °R <br /> | 21.2 | ~29.2 |
60°C333.15 K <br />140 °F <br />599.67 °R <br /> | ~29.1 | ~42.1 |
70°C343.15 K <br />158 °F <br />617.67 °R <br /> | ~37.0 | ~55.0 |
80°C353.15 K <br />176 °F <br />635.67 °R <br /> | ~44.9 | ~67.9 |
90°C363.15 K <br />194 °F <br />653.67 °R <br /> | 52.7 | 80.7 |
Gallery
Video
Sources
Borates | |
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Ammonium tetraborate ((NH4)2B4O7O) • Boric acid (H3BO3) • Copper(II) metaborate (Cu(BO2)2 · H2O) • Sodium tetraborate (Na2B4O7) |