Phosphate-containing substances dissolve in acid, transforming them to soluble orthophosphate ions (PO43-). With the addition of a single reagent, the soluble phosphate is readily precipitated as quinoline molybdophosphoric acid. The precipitate is simple to filter, dry, and weigh. No evaporation or heating is required.
The standard method for determining phosphate is as follows: A solution of sample is acidified with HCl, and then ammonium molybdate is added. The mixture is heated in a water bath until it reaches 100°C. It is then cooled in an ice/water bath for about 20 minutes and filtered through Whatman number 1 filter paper. The filter should be washed with deionized water and dried at 120°C for 12 hours before weighing to determine phosphate concentration in mg/L.
The precipitating agent for phosphate determination is ammonium molybdate. This reagent reacts with phosphates to form a yellow complex that is visible to the eye. The reaction is stoichiometric; therefore, no further phosphate recovery occurs. The disadvantage is that ammonium molybdate is toxic. Laboratory safety procedures must be followed when working with this material.
Ammonium molybdate has many applications in laboratory testing.
Phosphate, often known as PO4, is a phosphorus (P) molecule that is one of the top 14 trace elements present in natural seawater that are considered important for saltwater aquarium and reef tank systems. The usual PO4 concentration in the ocean is 0.07 ppm (remember this number for future reference). Marine phosphates occur in two forms: orthophosphate (oPO4) and pyrophosphate (PPi). Orthophosphate is the form that organisms use to build their skeletons and teeth; therefore, it is the most common form found in marine animals. Pyrophosphate occurs in small amounts in some marine organisms and is used as a source of energy. As well, it has been shown to be necessary for certain cellular processes such as signal transduction inside cells.
Orthophosphate is the only type of phosphate that should be added to marine aquariums. If pyrophosphate is added instead, this will cause the pH of the water to rise, which is not recommended unless instructed to do so by a professional aquarium supplier or dealer.
Marine phosphates are an essential part of any marine aquarium system. They play a crucial role in maintaining healthy coral reefs and sea gardens. Without sufficient phosphate, all the hardworking bacteria would die off, causing major problems for ocean wildlife and aquatic life in general. Phosphate levels can become depleted over time if proper care is not taken of your aquarium.
A phosphate, often known as an organophosphate, is an ester of phosphoric acid in organic chemistry. Phosphates can condense to generate pyrophosphates at high temperatures in the solid state. Sulfites, sometimes known as sulphites, are compounds containing the sulfite ion SO32-. The conjugate base of bisulfite is the ion sulfite. Phosphate and sulfite have very similar chemical properties. In fact, under basic conditions, they are interchangeable.
Phosphate is used in many medicines, such as penicillin and vancomycin, and in water treatment chemicals, such as Fenton's reagent and Lignosulfonates. It is also used as a flame retardant for plastics and textiles.
Sulfite is used in medicine and food processing and as a preservative in some nail polishes and lipstick. It is also found in some cleaning products and batteries.
Both phosphate and sulfite are anionic molecules with negative charges by definition. Anions are substances that exist in nature or are produced by humans that have a net charge-they have electrons available to give away. Phosphate and sulfite are both molecules with large polyatomic ions. Polyatomic ions are molecules that contain more than one atom, such as sodium (Na+), magnesium (Mg2+), potassium (K+), calcium (Ca2+), iron (Fe3+), copper (Cu2+), zinc (Zn2+) etc.
Potassium phosphate is found in three forms: monobasic (KH2PO4), dibasic (K2HPO4), and tribasic (K2HPO4). Depending on the required pH, neutral potassium phosphate buffer solutions can be made using a blend of monobasic and dibasic forms to variable degrees. For example, a solution containing 100 mM KH2PO4 and 0% K2HPO4 would have a pH of 2.86.
Monobasic and dibasic phosphates are used as buffers because they provide easy access to hydrogen ions for titration. Monobasic phosphate has an acidic pH while dibasic phosphate has a basic pH. By combining the two you get a range of pH values from 3.6 to 7.2. This is important because it allows you to control the acidity or alkalinity of the buffer depending on what kind of experiment you are doing. For example, if you were trying to break down proteins into their amino acids and remove ammonia as a by-product, then you would want to use a weak buffer such as potassium phosphate.
Tribasic phosphate has a pH greater than 7. However, due to its high pH, it is not useful for laboratory experiments unless you have sufficient reason to go beyond 7.0. Tribasic phosphate is used as a fertilizer because at these high concentrations it provides more alkaline phosphates when dissolved in water.
Phosphates are molecules that have the formula PO4-. Phosphates behave as nucleophiles in the presence of a negative charge; they seek a positive charge and are thus always found coupled to other atoms or molecules. The phosphorus atom has an electron deficiency, so it can accept electrons from other atoms or molecules. The resulting compound is called a salt.
Phosphate is a monovalent salt. This means that it contains only one negatively charged molecule. A divalent salt would contain two negatively charged molecules, and so on. Monovalent ions are the most common because they require a single charge to balance their electric charge. Divalent ions are less common because they need two charges to be balanced. Trivalent ions are even less common because they need three charges to be balanced.
Mono- vs. di- vs. tri-valent: Ions are classified by the number of negative charges they carry (the valence). Ions with one negative charge are called monovalent. Ions with two negative charges are called divalent. Ions with three negative charges are called trivalent.
Phosphate is a monomeric cation. This means that it is not part of a polyatomic ion. Polyatomic ions are ions that are composed of more than one atom or molecule.
O8PS-5-PubChem | Phosphate Sulfate | A salt derived from sulfuric acid and phosphoric acid. Sulfate salts are white or colorless, crystalline solids that dissolve in water to form a weak acid. They are used as fertilizers and flocculants for wastewater treatment.
Sulfate and phosphate are anorganic compounds with the formula SO4-2 and PO4-3, respectively. Sulfate is a polyatomic ion with a negative charge distributed over two oxygen atoms and four sulfur atoms, whereas phosphate has a positive charge distributed over three oxygen atoms and one phosphorus atom. The ions formed by these anions are called anhydrous salts because they do not contain any hydroxyl groups (–OH). Sulfate and phosphate anions can be combined with various cations to form compound salts. These combination products are used as fertilizers because of their high nitrogen content; they are also important components of rock dust and natural gas.
In chemistry, sulfate and phosphate esters are esters obtained by reacting sulfurous acid or its derivatives with alcohols or phenols.