Silver nitrate and sodium phosphate react to make silver phosphate and sodium nitrate. The diversity of the properties and uses of the starting compounds equally matches the diversity of the resulting. The unique chemical and physical properties of all four compounds make them suitable for applications ranging from medicine to photography, from laboratory reagents to ceramics, and many others in between.
Silver nitrate reacts with sodium phosphate in a double-displacement reaction. The silver (Ag) ions dissociate from the nitrate (NO3) ions while the sodium (Na) ions dissociate from the phosphate (PO4) ions. When the silver ions combine with phosphate ions, they form silver phosphate. When the sodium ions combine with the nitrate ions, they form sodium nitrate. The formation of silver phosphate drives chemical reaction due to the greater stability of silver phosphate compared to silver nitrate.
Best known for making mirrors, silver nitrate actually has many other uses. As a laboratory analytical reagent, silver nitrate tests for the presence of various ions through the different colors of the resulting silver compounds. Silver nitrate provides the stain in electron microscopy and for proteins and nucleic acids. In oil fields, silver nitrate helps determine quantity of chloride ions in the water as well as the exact amount of salt in seawater. Silver nitrate plays a role in the formation of silver-plated jewelry, hair dyes, inks, permanent fabric marker pens, photography, ceramics and the making of certain explosives. In the floral industry, silver nitrate prevents premature shrinking of buds and blooms and inhibits ripening in cut flowers. Silver nitrate cauterizes blood vessels, helps heal mouth ulcers and can remove warts, but it is poisonous if taken internally.
Sodium phosphate, or Na3PO4, contains three sodium (Na) atoms, one phosphorus (P) atom, and four oxygen (O) atoms per molecule of sodium phosphate. Sodium phosphate taken as a medicine helps completely empty your colon, or large intestine, before a colonoscopy or other procedure that needs to examine your empty bowel. Sodium phosphate, a saline laxative, works by causing diarrhea, causing you to empty all stool from your colon. This medicine can be very dangerous, causing acute phosphate nephropathy, a type of acute kidney injury associated with severe dehydration.
The reaction of silver nitrate with sodium phosphate produces silver phosphate. Silver phosphate has an exceptionally high melting point of about 1,560 degrees F, or 849 degrees C. The density of silver phosphate equals 6.37--more than the density of 4.35 calculated for silver nitrate. In photography, silver phosphate functions as a light sensitive agent, in photochemical splitting of water, and for the production of activated oxygen. In analytical chemistry, silver phosphate precipitates out solids, stains biological materials and can function to incorporate silver metal into other materials, giving them antibacterial properties.
The reaction of silver nitrate and sodium phosphate also produces sodium nitrate. Sodium nitrate has many synonyms including nitratine, nitric acid sodium salt, sodium saltpeter and sodium nitrate crystal. As a chemical formula, sodium nitrate looks like NaNO3, with one sodium (Na) atom, one nitrogen (N) atom and three oxygen (O) atoms for every molecule of sodium nitrate. Inhaling sodium nitrate directly may irritate your respiratory track, causing you to cough and experience shortness of breath. While used as a common food preservative, especially for deli meats, ingestion of the pure chemical may cause gastroenteritis, abdominal pains, dizziness, bloody diarrhea, headache, mental impairment, convulsions and collapse. Direct contact with your skin and eyes may cause irritation, redness, itching and pain.