Binary prefixes

Theorem 4-4 (Szilard, Kraft). A necessary and sufficient condition on the lengths n, 1 < j J, of the J code words of a binary prefix code is that... 

Theorem 4-5. Let Pr(ux), , Pr(u7) be the probabilities in decreasing order of the set of sequences of length N from a discrete memoryless source of entropy H(U). Then every binary prefix code for this source has an average length Nb satisfying... 

There are two major classes of data entities in the language - constants and variables. Constants can be decimal, binary (prefixed by and Ob ), and hexadecimal (prefixed by Ox ). Negative constants are represented using two s... 

Necessity Let vlt- -,vy be a set of binary sequences satisfying the prefix condition, and consider these sequences as binary fraction expansions of real numbers between 0 and 1 (i.e., 1011 corresponds to the number 1 x 2-1 + 1 x 2-3 + 1 x 2-4). Then if vy has length np no other code word, can fall in the interval... 

Dividing Eqs. (4-19) and (4-20) by N, we see that the average number of binary digits per source symbol for the best prefix condition code satisfies... 

Binary molecular compounds are named by using Greek prefixes to indicate the number of atoms of each element present the element named second has its ending changed to -ide. 

The written name of a compound includes the names of the elements it contains and information about the numbers of atoms of each element. The elements have to occur in some order, and this order is set by the same guidelines as for the chemical formula (see Section 3-11. Names can contain element names, roots derived from element names, and prefixes indicating the number of atoms of each element. Tables and 3 list the more important roots and prefixes that appear in the names of binaiy compounds. We can summarize the rules for naming binary compounds in three guidelines ... 

The table shows some of the prefixes used to name binary covalent compounds. What name would be given to the compound PBr5 ... 

To balance a chemical equation, the chemical formulas for the reactants are first written on the left-hand side of the equation. For example, in the reaction between hydrochloric acid and sodium hydroxide, the chemical formulas are HCl and NaOH, respectively. Remember that if an acid starts with the prefix hydro-, it is a binary acid. That means that hydrochloric acid is made up of only two... 

The first compounds to be discussed will be compounds of two nonmetals. These binary compounds are named with the element to the left or below in the periodic table named first. The other element is then named, with its ending changed to -ide and a prefix added to denote the number of atoms of that element present. If one of the elements is to the left and the other below, the one to the left is named first unless that element is oxygen or fluorine, in which case it is named last. The same order of elements is used in writing formulas for these compounds. (The element with the lower electronegativity is usually named first refer to Table 5-1.) The prefixes are presented in Table 6-2. The first six prefixes are the most important to memorize. 

Ans. The three compounds belong to different nomenclature classes. Aluminum in its compounds always forms 3+ ions, and thus there is no need to state 3+ in the name. Cobalt forms 2+ and 33-ions, and we need to designate which of these exists in this compound. PCI, is a binary nonmctal-nonmetal compound, using a prefix to denote the number of chlorine atoms. 

The binary metal carbonyls are named by giving the name of the metal followed by the name carbonyl, with the number of carbonyl groups indicated by the appropriate prefix. For example, Ni(CO)4 is nickel tetracarbonyl, whereas Cr(CO)6 is chromium hexacarbonyl. If more than one metal atom is present, the number is indicated by a prefix. Thus, Co2(CO)8 is dicobalt octacarbonyl, and Fe2(CO)9 has the name diiron nonacarbonyl. 

Many hydrogen compounds are acids. Acids require a different system of nomenclature than other compounds. There are two types of acids binary acids and ternary acids. All acids include the word acid in their name. Binary acids contain only two elements one of which is hydrogen and the other a nonmetal. When naming binary acids, the prefix hydro- appears before the root name of the nonmetal, and there will be an -ic suffix. As an acid, H2S would be hydrosulfuric acid. We used H2S to illustrate the fact that there can be two possible names, hydrogen sulfide or hydrosulfuric acid. If your instructor does not specify which name to use, either is correct. Technically, the name hydrosulfuric acid only applies to aqueous solutions of H2S, H2S(aq). 

To write the formula from the name of a binary compound containing only nonmetals, simply write the symbols for the separate atoms with the prefixes converted to subscripts. 

In naming compounds, don t confuse metal and nonmetal type binary compounds. Prefixes are used only with nonmetal types. 

Naming binary molecular compounds requires using Greek prefixes to indicate the number of atoms of each element in the compound or molecule. Prefixes are given in Table 1.4. Prefixes precede each element to indicate the number of atoms in the molecular compound. The stem of the second element takes the ide suffix. The prefix mon is dropped for the initial element that is, if no prefix is given, it is assumed that the prefix is 1. Examples of molecular compounds are carbon dioxide (C02), carbon monoxide (CO), and dinitrogen tetroxide (N204). 

The temperature of initial crystallization of one of the components of a binary system on cooling is not a CST or cloud point. Some confusion exists in the literature from reporting crystallization points as CST. Many such observations have been corrected for use in these tables by placing the prefix < before the temperature. 

Binary npe nomenclature. In this system, the composition of a substance is specified by ihe juxtaposition of dement group names, modified or unmodified, together with appropriate numerical prefixes, if considered necessary. 

Additive nomenclature1 is based on the combination of element names or roots of element names and/or ligand names. The simplest and oldest additive nomenclature is binary nomenclature that expresses two components, e.g. sodium chloride. The cationic or electropositive portion of the compound expressed in a binary name is the element name unchanged or a group name ending in -ium , and the anionic or electronegative portion of a compound expressed in the name ends in -ide, -ite or -ate. The proportions of cations and anions in neutral compounds are indicated by Stock numbers or simple or multiplicative prefixes (see Section 3.3.2). Additive nomenclature denotes composition. For examples see Table 1. 

Modified Forms in Common Use. There are numerous situations in which the foregoing system does not meet all requirements. In the formation uf binary compounds, several elements exhibit more Ilian two states of oxidation. One method, recommended by the IUPAC, of handling these situations is the use of prefixes derived from Greek to indicate stoichiometric composition, e.g., titanium dichloride, TiCL and dinitrogen oxide (nitrous oxide) N 0. Other accepted methods ofindicating proportions of constituents are the Stock system (oxidation number) and the Ewens-Bassett (charge number) system. 

Many simple inorganic molecular compounds are named by using the Greek prefixes in Table D.2 to indicate the number of each type of atom present. Usually, no prefix is used if only one atom of an element is present an important exception to this rule is carbon monoxide, CO. Most of the common binary molecular compounds—molecular compounds built from two elements—have at least one element from Group 16 or 17. These elements are named second, with their endings changed to -ide ... 

Because nonmetals often combine in different proportions to form different compounds, numerical prefixes are usually included in the names of binary molecular compounds to specify the numbers of each kind of atom present. The... 

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