Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Disodium phosphate
open-in-new
<p>Disodium phosphate (DSP), or disodium hydrogen phosphate, or sodium phosphate dibasic, is an <a href="/facts/Inorganic_compound/TfFfzxSz">inorganic compound</a> with the <a href="/facts/Chemical_formula/hghUtthl">chemical formula</a> <a href="/facts/Sodium/eYuSPu2V">Na</a>2<a href="/facts/Hydrogen/BoYHjl0J">H</a><a href="/facts/Phosphorus/27xCeIqs">P</a><a href="/facts/Oxygen/acyn6o8r">O</a>4. It is one of several <a href="/facts/Sodium_phosphates/zVdGWhfC">sodium phosphates</a>. The <a href="/facts/Salt_(chemistry)/lsSKwGpn">salt</a> is known in <a href="/facts/Anhydrous/A7B0fDLE">anhydrous</a> form as well as <a href="/facts/Hydrates/dev82l69">hydrates</a> Na2HPO4·<i>n</i>H2O, where <i>n</i> is 2, 7, 8, and 12. All are water-soluble white powders. The anhydrous salt is <a href="/facts/Hygroscopic/1NBGewXv">hygroscopic</a>. </p><p>The <a href="/facts/PH/RnSv8D7y">pH</a> of disodium hydrogen phosphate water solution is between 8.0 and 11.0, meaning it is moderately <a href="/facts/Base_(chemistry)/M9wA7qeM">basic</a>: </p> HPO2−4 + H2O ⇌ H2PO−4 + OH−