Chemical formulas hydrates

Chemical Designations - Synonyms Ammonium Oxalate Hydrate Diammonium Oxalate Oxalic Acid, Diammonium Salt Chemical Formula (NH,)2C204 H20. 

Chemical Designations - Synonyms Calcium Chloride, Anhydrous Calcium Chloride Hydrates Chemical Formula CaClj-xHjO where x=o to 6. 

Chemical Designations - Synonyms Ammonium ferric citrate, Ferric ammonium citrate (brown), Ferric ammonium citrate (green) Chemical Formula Mixture of FeC HjOy, (NiyjHCjjHjOy, and water of hydration. 

Many ionic compounds can have water molecules incorporated into their solid structures. Such compounds are called hydrates. To emphasize the presence of discrete water molecules in the chemical structure, the formula of any hydrate shows the waters of hydration separated from the rest of the chemical formula by a dot. A coefficient before H2 O indicates the number of water molecules in the formula. Copper(II) sulfate pentahydrate is a good example. The formula of this beautiful deep blue solid is C11SO4 5 H2 O, indicating that five water molecules are associated with each CuSOq unit. Upon prolonged heating, CuSOq 5 H2 O loses its waters of hydration along with its color. Other examples of hydrates include aluminum nitrate nonahydrate, A1 (N03)3 9 H2 O,... 

A50.00-g sample of hydrated manganese(II) chloride yields 31.75 g of the anhydrous compound after heating. Determine the chemical formula and name of the hydrate. 

Epsom salts, for example, consist of crystals of magnesium sulfate heptahydrate, MgS04-7H20. Every formula unit of magnesium sulfate has seven molecules of water weakly bonded to it. A raised dot in a chemical formula, in front of one or more water molecules, denotes a hydrated compound. Note that the dot does not include multiplication, but rather a weak bond between an ionic compound and one or more water molecules. Some other examples of hydrates are shown in Table 6.4. 

The following Sample Problem shows how to find the percent by mass of water in a hydrate. It also shows how to determine the formula of a hydrate based on an incomplete chemical formula. 

Here we compare the thermodynamic parameters of trehalose, maltose and sucrose because they have the same chemical formula (C12H22O11) and mass (molecular weight 342.3), but different structures which could be responsible for their different hydration properties. The anomaly of hydration of trehalose is understood from the following observation [10]. Namely, the amount of water used for the preparation of 1.5 M trehalose solution is smaller than the amount used for the preparation of other sugar solutions. In a 1.5 M solution, trehalose itself occupies 37.5% of the volume of the solution. However, in a 1.5 M solution, sucrose occupies 13% and maltose occupies 14%. These data suggest that trehalose has a larger hydrated volume than the other sugars. This hypothesis can be demonstrated from various thermodynamic parameters as shown in Table 12.1. 

Amino acids of the general form, 1, are the monomeric molecules which are condensed to form the polypeptide chains of the fibrous and globular proteins. The naturally occurring molecules are the L-enantiomers, shown in 1 for chemical formulae see Fig. 19.1. D-amino acids can be synthesized and the individual L- or D-amino acids or the D,Lrracemates can be crystallized. All the common amino acids have been studied by neutron or X-ray crystal structure analysis (see Thble 14.1), in the anhydrous or hydrate forms, as hydrochlorides or hydrochloride hydrates. 

The name clathrate, from the Greek klathron KXaOpov, bolt or lock, since the volatile guest compound is locked into the crystal), was coined by Herbert M. Powell, who studied many of them. Examples of clathrates are provided by the gas hydrates, first identified by Sir Humphrey Davy, who prepared chlorine hydrate by bubbling chlorine into cool water. This hydrate was shown to have the chemical formula 8CI2 46H2O. The anesthetic properties of chloroform have been attributed to the formation of such gas hydrates in brain tissue. ... 

Analyzing the term carbohydrate offers a hint about the structure of this group of molecules. Early observations that these compounds have the general chemical formula C (H20) and appear to be hydrates of carbon led to their being called carbohydrates. Although it is now known that there are no full water molecules attached to carbohydrates, the name has stayed. 

Carbohydrates form a class of compounds of carbon with hydrogen and oxygen. The name comes from the chemical formulas of these compounds, which can be written C (H20) suggesting a hydrate of carbon. Simple sugars, or monosaccharides, are carbohydrates with the chemical formula C H2 0 . Sugars with three, four, five, and six carbon atoms are called trioses, tetroses, pentoses, and hexoses, respectively. 

Studies of crystal structures have led to the revision of many chemical formulae by regrouping the atoms to correspond to the actual groups present in the crystal. This is particularly true of compounds originally formulated as hydrates some examples follow. 

Figure 5. The generalized reaction surface for the chosen hydration scheme of the Pt(II) complexes. In the fraction, cis/trans under the chemical formula means that the cis isomer lies higher than the corresponding trans isomer. The complexes lying higher than 50 kcal/mol are not shown for the sake of lucidity.

Lithium hypochlorite can be obtained by mixing strong solutions of sodium hypochlorite with lithium chloride. This results in partial precipitation of sodium chloride. The product obtained by evaporation of supematent solution typically contains 30% lithium hypochlorite (LiOCl), 34% sodium chloride and other salts. Chlorinated trisodium phosphate is a hydrated complex having chemical formula (Naj PO. H3O) NaOCl and contains approximately 4% available chlorine. Gener-... 

Chemical formula 86205 or IISb(Oll)(, in hydrated form Functionality OH... 

Chemical formula Na2SO3 (anhydrous) Mol.wt. 126.04, c/2°4 2.633 Hydrated Na2SO3-7H2O... 

Chemical formulas describe the simplest atom ratio (empirical formula), actual atom number (molecular formula), and atom arrangement (structural formula) of one unit of a compound. An ionic compound is named with cation first and anion second. For metals that can form more than one ion, the charge is shown with a Roman numeral. Oxoanions have suffixes, and sometimes prefixes, attached to the element root name to indicate the number of oxygen atoms. Names of hydrates give the number of associated water molecules with a numerical prefix. Acid names are based on anion names. Covalent compounds have the first word of the name for the element that is leftmost or lower down in the periodic table, and prefixes show the number of each atom. The molecular (or formula) mass of a compound is the sum of the atomic masses in the formula. Molecules are depicted by various types of formulas and models. 

Chemical Designations - Synonyms 2-Butanol Butylene Hydrate 2-Hydroxybutane Methylethylcarbinol Chemical Formula CH3CH2CH(OH)CH3. 

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