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59-478: Lignosulfonates have very broad ranges of molecular mass (they are very polydisperse ). A range of from 1,000 to 140,000 Da has been reported for softwood lignosulfonates with lower values reported for hardwoods. Sulfonated Kraft lignin tends to have smaller molecules at 2,000–3,000 Da. SL and LS are non-toxic, non-corrosive, and biodegradable . A range of further modifications may be applied to LS and SL, including oxidation, hydroxymethylation, sulfomethylation, and

118-403: A tannin for tanning leather and as a feedstock for a variety of products. The single largest use for lignosulfonates is as plasticizers in making concrete , where they allow concrete to be made with less water (giving stronger concrete) while maintaining the ability of the concrete to flow. Lignosulfonates are also used during the production of cement , where they act as grinding aids in

177-466: A combination thereof. Lignosulfonates are recovered from the spent pulping liquids (red or brown liquor) from sulfite pulping. Ultrafiltration can also be used to separate lignosulfonates from the spent pulping liquid. A list of CAS numbers for the various metal salts of lignosulfonate is available. The electrophilic carbocations produced during ether cleavage react with bisulfite ions (HSO 3 ) to give sulfonates. The primary site for ether cleavage

236-432: A constituent of the paste used to coat the lead-antimony-calcium or lead-antimony-selenium grids in a Lead-acid battery . Aqueous lignosulfonate solutions are also widely used as a non-toxic dust suppression agent for unpaved road surfaces, where it is popularly, if erroneously, called "tree sap". Roads treated with lignosulfonates can be distinguished from those treated with calcium chloride by color: lignosulfonates give

295-442: A conversion factor, describing the shape of a particular molecule. This allows the apparent molecular mass to be described from a range of techniques sensitive to hydrodynamic effects, including DLS , SEC (also known as GPC when the eluent is an organic solvent), viscometry , and diffusion ordered nuclear magnetic resonance spectroscopy (DOSY). The apparent hydrodynamic size can then be used to approximate molecular mass using

354-549: A distinctive bitter flavor alongside its salty taste. The bitterness is attributable to the calcium ions and their interaction with human taste receptors: certain members of the TAS2R family of bitter taste receptors respond to calcium ions; the bitter perception of calcium is thought to be a protective mechanism to avoid ingestion of toxic substances, as many poisonous compounds taste bitter. While chloride ions (Cl⁻) primarily contribute to saltiness, at higher concentrations, they can enhance

413-656: A hard amalgamated solid when cooled. Similarly, CaCl 2 is used as a flux and electrolyte in the FFC Cambridge electrolysis process for titanium production, where it ensures the proper exchange of calcium and oxygen ions between the electrodes. Calcium chloride infusions may be used as an intravenous therapy to prevent hypocalcemia . Calcium chloride is a highly soluble calcium salt. Hexahydrate calcium chloride (CaCl 2 ·6H 2 O) has solubility in water of 811 g/L at 25 °C. Calcium chloride when taken orally completely dissociates into calcium ions (Ca ) in

472-429: A liquid ballast, aiding traction in cold climates. It is also used in domestic and industrial chemical air dehumidifiers . The second largest application of calcium chloride exploits its hygroscopic nature and the tackiness of its hydrates; calcium chloride is highly hygroscopic and its hydration is an exothermic process . A concentrated solution keeps a liquid layer on the surface of dirt roads , which suppresses

531-529: A series of macromolecule-specific standards. As this requires calibration, it's frequently described as a "relative" molecular mass determination method. It is also possible to determine absolute molecular mass directly from light scattering, traditionally using the Zimm method . This can be accomplished either via classical static light scattering or via multi-angle light scattering detectors. Molecular masses determined by this method do not require calibration, hence

590-427: A substance. The definition of molecular weight is most authoritatively synonymous with relative molecular mass; however, in common practice, use of this terminology is highly variable. When the molecular weight is given with the unit Da, it is frequently as a weighted average similar to the molar mass but with different units. In molecular biology, the mass of macromolecules is referred to as their molecular weight and

649-537: A weighted average of a sample. Prior to the 2019 revision of the SI quantities expressed in daltons (Da) were by definition numerically equivalent to molar mass expressed in the units g/mol and were thus strictly numerically interchangeable. After the 2019 revision, this relationship is only nearly equivalent, although the difference is negligible for all practical purposes. The molecular mass of small to medium size molecules, measured by mass spectrometry, can be used to determine

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708-419: A wide range of molecular masses (40 kDa – 5 MDa). To a first approximation, the basis for determination of molecular mass according to Mark–Houwink relations is the fact that the intrinsic viscosity of solutions (or suspensions ) of macromolecules depends on volumetric proportion of the dispersed particles in a particular solvent. Specifically, the hydrodynamic size as related to molecular mass depends on

767-409: Is CH 4 , are calculated respectively as follows: The uncertainty in molecular mass reflects variance (error) in measurement not the natural variance in isotopic abundances across the globe. In high-resolution mass spectrometry the mass isotopomers C H 4 and C H 4 are observed as distinct molecules, with molecular masses of approximately 16.031 Da and 17.035 Da, respectively. The intensity of

826-648: Is also an ingredient used in ceramic slipware . It suspends clay particles so that they float within the solution, making it easier to use in a variety of slipcasting techniques. For watering plants to use as a fertilizer, a moderate concentration of calcium chloride is used to avoid potential toxicity: 5 to 10 mM (millimolar) is generally effective and safe for most plants—that is 0.55–1.11 grams (0.019–0.039 oz) of anhydrous calcium chloride ( CaCl 2 ) per liter of water or 1.10–2.19 grams (0.039–0.077 oz) of calcium chloride hexahydrate ( CaCl 2 ·6 H 2 O ) per liter of water. Calcium chloride solution

885-458: Is also used in firming soybean curds into tofu and in producing a caviar substitute from vegetable or fruit juices . It is also used to enhance the texture of various other products, such as whole apples, whole hot peppers, whole and sliced strawberries, diced tomatoes, and whole peaches. The firming effect of calcium chloride can be attributed to several mechanisms: Calcium chloride's freezing-point depression properties are used to slow

944-561: Is also used to provide inhibition of swelling clays in the water phase of invert emulsion drilling fluids. Calcium chloride ( CaCl 2 ) acts as flux material , decreasing the melting point, in the Davy process for the industrial production of sodium metal through the electrolysis of molten NaCl . Calcium chloride is also used in the production of activated charcoal . Calcium chloride can be used to precipitate fluoride ions from water as insoluble CaF 2 . Calcium chloride

1003-463: Is approximately 27.2%. This means that for every gram of calcium chloride hexahydrate, there are about 272 milligrams of elemental calcium. For anhydrous calcium chloride (CaCl 2 ), the elemental calcium content is slightly higher, around 28.4% (for every gram of anhydrous calcium chloride there are about 284 milligrams of elemental calcium). Calcium chloride has a very salty taste and can cause mouth and throat irritation at high concentrations, so it

1062-406: Is commonly encountered as a hydrated solid with generic formula CaCl 2 · n H 2 O , where n = 0, 1, 2, 4, and 6. These compounds are mainly used for de-icing and dust control. Because the anhydrous salt is hygroscopic and deliquescent , it is used as a desiccant . Calcium chloride was apparently discovered in the 15th century but wasn't studied properly until the 18th century. It

1121-424: Is defined in terms of the mass of the isotope C (carbon-12). However, the name unified atomic mass unit (u) is still used in common practice. Relative atomic and molecular masses as defined are dimensionless . Molar masses when expressed in g / mol have almost identical numerical values as relative atomic and molecular masses. For example, the molar mass and molecular mass of methane , whose molecular formula

1180-447: Is expressed in kDa, although the numerical value is often approximate and representative of an average. The terms "molecular mass", "molecular weight", and "molar mass" may be used interchangeably in less formal contexts where unit- and quantity-correctness is not needed. The molecular mass is more commonly used when referring to the mass of a single or specific well-defined molecule and less commonly than molecular weight when referring to

1239-432: Is illustrated by the fact that these solutions react with phosphate sources to give a solid precipitate of calcium phosphate : Calcium chloride has a very high enthalpy change of solution , indicated by considerable temperature rise accompanying dissolution of the anhydrous salt in water. This property is the basis for its largest-scale application. Aqueous solutions of calcium chloride tend to be slightly acidic due to

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1298-670: Is injected into the testes of the animal. Within one month, necrosis of testicular tissue results in sterilization. Cocaine producers in Colombia import tons of calcium chloride to recover solvents that are on the INCB Red List and are more tightly controlled. Although the salt is non-toxic in small quantities when wet, the strongly hygroscopic properties of non-hydrated calcium chloride present some hazards. It can act as an irritant by desiccating moist skin. Solid calcium chloride dissolves exothermically , and burns can result in

1357-546: Is permitted as a food additive in the European Union for use as a sequestrant and firming agent with the E number E509 . It is considered as generally recognized as safe (GRAS) by the U.S. Food and Drug Administration. Its use in organic crop production is generally prohibited under the US National Organic Program . The elemental calcium content in calcium chloride hexahydrate (CaCl 2 ·6H 2 O)

1416-500: Is sometimes added to processed (pasteurized/homogenized) milk to restore the natural balance between calcium and protein in casein . It is added before the coagulant. Calcium chloride is also commonly used as an " electrolyte " in sports drinks and other beverages; as a food additive used in conjunction with other inorganic salts it adds taste to bottled water . The average intake of calcium chloride as food additives has been estimated to be 160–345 mg/day. Calcium chloride

1475-400: Is the α-carbon (carbon atom attached to the aromatic ring) of the propyl (linear three carbon) side chain. The following structures do not specify the structure since lignin and its derivatives are complex mixtures: the purpose is to give a general idea of the structure of lignosulfonates. The groups R and R can be a wide variety of groups found in the structure of lignin. Sulfonation occurs on

1534-514: Is typically not the first choice for long-term oral supplementation (as a calcium supplement ). Calcium chloride, characterized by its low molecular weight and high water solubility, readily breaks down into calcium and chloride ions when exposed to water. These ions are efficiently absorbed from the intestine. However, caution should be exercised when handling calcium chloride, for it has the potential to release heat energy upon dissolution in water. This release of heat can lead to trauma and burns in

1593-462: Is used immediately after preparation to prevent potential alterations in its chemical composition. Besides that, calcium chloride is highly hygroscopic, meaning it readily absorbs moisture from the air. If the solution is left standing, it can absorb additional water vapor, leading to dilution and a decrease in the intended concentration. Prolonged standing may lead to the precipitation of calcium hydroxide or other insoluble calcium compounds, reducing

1652-570: Is used to prevent ice formation and is used to de-ice . This application consumes the greatest amount of calcium chloride. Calcium chloride is relatively harmless to plants and soil. As a de-icing agent, it is much more effective at lower temperatures than sodium chloride . When distributed for this use, it usually takes the form of small, white spheres a few millimeters in diameter, called prills . Solutions of calcium chloride can prevent freezing at temperatures as low as −52 °C (−62 °F), making it ideal for filling agricultural implement tires as

1711-430: The cement mill and as a rawmix slurry deflocculant (that reduces the viscosity of the slurry). Lignosulfonates are also used for the production of plasterboard to reduce the amount of water required to make the stucco flow and form the layer between two sheets of paper. The reduction in water content allows lower kiln temperatures to dry the plasterboard, saving energy. The ability of lignosulfonates to reduce

1770-408: The composition of elements in the molecule. The molecular masses of macromolecules, such as proteins, can also be determined by mass spectrometry; however, methods based on viscosity and light-scattering are also used to determine molecular mass when crystallographic or mass spectrometric data are not available. Molecular masses are calculated from the atomic masses of each nuclide present in

1829-434: The halogens ( group 17) typically occur. Calcium chloride occurs as the rare evaporite minerals sinjarite (dihydrate) and antarcticite (hexahydrate). Another natural hydrate known is ghiaraite – a tetrahydrate. The related minerals chlorocalcite (potassium calcium chloride, KCaCl 3 ) and tachyhydrite (calcium magnesium chloride, Ca Mg 2 Cl 6 ·12 H 2 O ) are also very rare. The same

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1888-430: The mouth and esophagus if it is ingested. Ingestion of concentrated solutions or solid products may cause gastrointestinal irritation or ulceration . Consumption of calcium chloride can lead to hypercalcemia . Calcium chloride dissolves in water, producing chloride and the aquo complex [Ca(H 2 O) 6 ] . In this way, these solutions are sources of "free" calcium and free chloride ions. This description

1947-428: The absorption and retention of fertilizers and other nutrients. It is able to chelate minerals while remaining bio-degradable, an improvement compared to EDTA . Further hydrolysis and oxidation produces a product even more similar to humus , marketed as "lignohumate". Molecular mass The molecular mass ( m ) is the mass of a given molecule . Units of daltons (Da) are often used. Different molecules of

2006-553: The activation of bitterness receptors. Calcium chloride is used in concrete mixes to accelerate the initial setting, but chloride ions lead to corrosion of steel rebar , so it should not be used in reinforced concrete . The anhydrous form of calcium chloride may also be used for this purpose and can provide a measure of the moisture in concrete. Calcium chloride is included as an additive in plastics and in fire extinguishers , in blast furnaces as an additive to control scaffolding (clumping and adhesion of materials that prevent

2065-446: The availability of calcium ions in the solution and reducing the effectiveness of the solution as a calcium source for plants. Nutrient solutions can become a medium for microbial growth if stored for extended periods. Microbial contamination may alter the composition of the solution and potentially introduce pathogens to the plants. When dissolved in water, calcium chloride can undergo hydrolysis, especially over time, which can lead to

2124-406: The bitter sensation. The combination of calcium and chloride ions intensifies the overall bitterness. At lower concentrations, calcium chloride may taste predominantly salty. The salty taste arises from the electrolyte nature of the compound, similar to sodium chloride (table salt). As the concentration increases, the bitter taste becomes more pronounced: the increased presence of calcium ions enhances

2183-409: The choice of isotopes is defined and thus is a single specific molecular mass out of the (perhaps many) possibilities. The masses used to compute the monoisotopic molecular mass are found in a table of isotopic masses and are not found in a typical periodic table. The average molecular mass is often used for larger molecules, since molecules with many atoms are often unlikely to be composed exclusively of

2242-494: The formation of dust. It keeps the finer dust particles on the road, providing a cushioning layer. If these are allowed to blow away, the large aggregate begins to shift around and the road breaks down. Using calcium chloride reduces the need for grading by as much as 50% and the need for fill-in materials as much as 80%. In the food industry, calcium chloride is frequently employed as a firming agent in canned vegetables, particularly for canned tomatoes and cucumber pickles. It

2301-438: The formation of small amounts of hydrochloric acid and calcium hydroxide: Ca 2 +2 H 2 O ⇌ Ca(OH) 2 +2 H . This reaction can lower the pH of the solution, making it more acidic. Acidic solutions may harm plant tissues and disrupt nutrient uptake. Calcium chloride dihydrate (20 percent by weight) dissolved in ethanol (95 percent ABV) has been used as a sterilant for male animals. The solution

2360-408: The freezing of the caramel in caramel-filled chocolate bars. Also, it is frequently added to sliced apples to maintain texture. In brewing beer, calcium chloride is sometimes used to correct mineral deficiencies in the brewing water. It affects flavor and chemical reactions during the brewing process, and can also affect yeast function during fermentation. In cheesemaking , calcium chloride

2419-430: The furnace charge from descending), and in fabric softener as a thinner. The exothermic dissolution of calcium chloride is used in self-heating cans and heating pads . Calcium chloride is used as a water hardener in the maintenance of hot tub water, as insufficiently hard water can lead to corrosion and foaming. In the oil industry , calcium chloride is used to increase the density of solids-free brines . It

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2478-421: The gastrointestinal tract, resulting in readily bioavailable calcium. The high concentration of calcium ions facilitates efficient absorption in the small intestine. However, the use of calcium chloride as a source of calcium taken orally is less common compared to other calcium salts because of potential adverse effects such as gastrointestinal irritation and discomfort. When tasted, calcium chloride exhibits

2537-444: The influence of the chloride ions on the hydrogen ion concentration in water. The slight acidity of calcium chloride solutions is primarily due to the increased ionic strength of the solution, which can influence the activity of hydrogen ions and lower the pH slightly. The pH of calcium chloride in aqueous solution is the following: Molten calcium chloride can be electrolysed to give calcium metal and chlorine gas: In much of

2596-417: The lignin. Oxidation of dimethyl sulfide with nitrogen dioxide produces dimethyl sulfoxide (DMSO). The anti-oxidant effect of lignosulfonates is utilized in feeds, ensilage and flame retardants. The UV absorbance of lignosulfonates is utilized in sun screens and bio-pesticides. Lignosulfonate is used in agriculture as an analogue of humic substances . As a soil conditioner , it is mainly used to enhance

2655-418: The mass of a given substance divided by the amount of the substance , and is expressed in grams per mol (g/mol). That makes the molar mass an average of many particles or molecules (potentially containing different isotopes ), and the molecular mass the mass of one specific particle or molecule. The molar mass is usually the more appropriate quantity when dealing with macroscopic (weigh-able) quantities of

2714-420: The mass-spectrometry peaks is proportional to the isotopic abundances in the molecular species. C H H 3 can also be observed with molecular mass of 17 Da. In mass spectrometry, the molecular mass of a small molecule is usually reported as the monoisotopic mass : that is, the mass of the molecule containing only the most common isotope of each element. This also differs subtly from the molecular mass in that

2773-664: The molecular mass of proteins, lipids, sugars and nucleic acids at the single-molecule level. The technique is based on interferometric scattered light microscopy. Contrast from scattered light by a single binding event at the interface between the protein solution and glass slide is detected and is linearly proportional to the mass of the molecule. This technique can also be used to measure sample homogeneity, to detect protein oligomerisation states, and to identify complex macromolecular assemblies ( ribosomes , GroEL , AAV ) and protein interactions such as protein-protein interactions. Mass photometry can accurately measure molecular mass over

2832-601: The molecule, while molar masses and relative molecular masses (molecular weights) are calculated from the standard atomic weights of each element . The standard atomic weight takes into account the isotopic distribution of the element in a given sample (usually assumed to be "normal"). For example, water has a molar mass of 18.0153(3) g/mol, but individual water molecules have molecular masses which range between 18.010 564 6863(15) Da ( H 2 O) and 22.027 7364(9) Da ( H 2 O). Atomic and molecular masses are usually reported in daltons , which

2891-449: The most abundant isotope of each element. A theoretical average molecular mass can be calculated using the standard atomic weights found in a typical periodic table. The average molecular mass of a very small sample, however, might differ substantially from this since a single sample average is not the same as the average of many geographically distributed samples. Mass photometry (MP) is a rapid, in-solution, label-free method of obtaining

2950-426: The mouth, throat, esophagus , and stomach. In fact, there have been reported cases of stomach necrosis resulting from burns caused by accidental ingestions of big amounts of undissolved calcium chloride. The extremely salty taste of calcium chloride is used to flavor pickles without increasing the food's sodium content. Calcium chloride is used to prevent cork spot and bitter pit on apples by spraying on

3009-663: The road surface a dark grey color, while calcium chloride lend the road surface a distinctive tan or brown color. As lignosulfonates do not rely on water to provide their binding properties, they tend to be more useful in arid locations. It is used as a soil stabilizer . Oxidation of lignosulfonates from softwood trees produced vanillin (artificial vanilla flavor). Dimethyl sulfide and dimethyl sulfoxide (an important organic solvent ) are produced from lignosulfonates. The first step involves heating lignosulfonates with sulfides or elemental sulfur to produce dimethyl sulfide. The methyl groups come from methyl ethers present in

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3068-401: The same compound may have different molecular masses because they contain different isotopes of an element. The derived quantity relative molecular mass is the unitless ratio of the mass of a molecule to the atomic mass constant (which is equal to one dalton). The molecular mass and relative molecular mass are distinct from but related to the molar mass . The molar mass is defined as

3127-433: The side chains, not on the aromatic ring like in p-toluenesulfonic acid . Kraft lignin from black liquor, which is produced in much higher amounts, may be processed into sulfonated lignin. The lignin is first precipitated by acidifying the liquor with CO 2 then washed (other methods for isolation exist). Reaction with sodium sulfite or sodium bisulfite and an aldehyde under a basic environment completes sulfonation. Here

3186-399: The sulfonic acid groups end up on the aromatic ring instead of the aliphatic sidechain. LS and SL have a wide variety of applications. They are used to stably disperse pesticides , dyes , carbon black , and other insoluble solids and liquids into water. As a binder it suppresses dust on unpaved roads. It is also a humectant and a in water treatment . Chemically, it may be used as

3245-478: The term "absolute". The only external measurement required is refractive index increment , which describes the change in refractive index with concentration. Calcium chloride Calcium chloride is an inorganic compound , a salt with the chemical formula CaCl 2 . It is a white crystalline solid at room temperature, and it is highly soluble in water. It can be created by neutralising hydrochloric acid with calcium hydroxide . Calcium chloride

3304-456: The tree during the late growing season. Drying tubes are frequently packed with calcium chloride. Kelp is dried with calcium chloride for use in producing sodium carbonate . Anhydrous calcium chloride has been approved by the FDA as a packaging aid to ensure dryness (CPG 7117.02). The hydrated salt can be dried for re-use but will dissolve in its own water of hydration if heated quickly and form

3363-590: The viscosity of mineral slurries ( deflocculation ) is used to advantage in oil drilling mud , where it replaced tannic acids from quebracho (a tropical tree). Furthermore, lignosulphates are being researched for use in enhanced oil recovery (EOR) due to their ability to reduce interfacial tension in foams, allowing for improved sweep efficiency, and hence increased recovery factor. Besides their use as dispersants lignosulfonates are also good binders. They are used as binders in well-paper, particle boards, linoleum flooring, coal briquettes, and roads. They also form

3422-561: The world, calcium chloride is derived from limestone as a by-product of the Solvay process , which follows the net reaction below: North American consumption in 2002 was 1,529,000 tonnes (3.37 billion pounds). In the US, most calcium chloride is obtained by purification from brine . As with most bulk commodity salt products, trace amounts of other cations from the alkali metals and alkaline earth metals ( groups 1 and 2) and other anions from

3481-414: Was historically called "fixed sal ammoniac " ( Latin : sal ammoniacum fixum ) because it was synthesized during the distillation of ammonium chloride with lime and was nonvolatile (while the former appeared to sublime ); in more modern times (18th-19th cc.) it was called "muriate of lime" ( Latin : murias calcis, calcaria muriatica ). By depressing the freezing point of water, calcium chloride

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