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Stochiometry
Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions. Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equals the total mass of the products, leading to the insight that the relations among quantities of reactants and products typically form a ratio of positive integers. This means that if the amounts of the separate reactants are known, then the amount of the product can be calculated. Conversely, if one reactant has a known quantity and the quantity of the products can be empirically determined, then the amount of the other reactants can also be calculated. This is illustrated in the image here, where the balanced equation is: : Here, one molecule of methane reacts with two molecules of oxygen gas to yield one molecule of carbon dioxide and two molecules of water. This particular chemical equation is an example of complete combustion. Sto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combustion Reaction Of Methane
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion does not always result in fire, because a flame is only visible when substances undergoing combustion vaporize, but when it does, a flame is a characteristic indicator of the reaction. While the activation energy must be overcome to initiate combustion (e.g., using a lit match to light a fire), the heat from a flame may provide enough energy to make the reaction self-sustaining. Combustion is often a complicated sequence of elementary reaction, elementary Radical (chemistry), radical reactions. Solid fuels, such as wood and coal, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them. Combustion is often hot enough that incandescence, incandescent light in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeremias Benjamin Richter
Jeremias Benjamin Richter (; 10 March 1762 – 4 May 1807) was a German chemist. He was born at Hirschberg in Silesia, became a mining official at Breslau in 1794, and in 1800 was appointed assessor to the department of mines and chemist to the royal porcelain factory at Berlin, where he died. He is known for introducing the term ''stoichiometry''. Developer of titration He made some of the earliest known determinations of the quantities by weight in which acids saturate bases and bases acids. He realised that those amounts of different bases which can saturate the same quantity of a particular acid are equivalent to each other (see ''Titration''). He was thus led to conclude that chemistry is a branch of applied mathematics and to endeavour to trace a law according to which the quantities of different bases required to saturate a given acid formed an arithmetical progression, and the quantities of acids saturating a given base a geometric progression. Law of definite propor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Transmutation
Nuclear transmutation is the conversion of one chemical element or an isotope into another chemical element. Nuclear transmutation occurs in any process where the number of protons or neutrons in the nucleus of an atom is changed. A transmutation can be achieved either by nuclear reactions (in which an outside particle reacts with a nucleus) or by radioactive decay, where no outside cause is needed. Natural transmutation by stellar nucleosynthesis in the past created most of the heavier chemical elements in the known existing universe, and continues to take place to this day, creating the vast majority of the most common elements in the universe, including helium, oxygen and carbon. Most stars carry out transmutation through fusion reactions involving hydrogen and helium, while much larger stars are also capable of fusing heavier elements up to iron late in their evolution. Elements heavier than iron, such as gold or lead, are created through elemental transmutations that can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Law Of Reciprocal Proportions
The law of reciprocal proportions also called law of equivalent proportions or law of permanent ratios is one of the basic laws of stoichiometry. It relates the proportions in which elements combine across a number of different elements. It was first formulated by Jeremias Richter in 1791. A simple statement of the law is:- :If element A combines with element B and also with C, then, if B and C combine together, the proportion by weight in which they do so will be simply related to the weights of B and C which separately combine with a constant weight of A. :As an example, 1 gram of sodium (Na = A) is observed to combine with either 1.54 grams of chlorine (Cl = B) or 5.52 grams of iodine (I = C). (These ratios correspond to the modern formulas NaCl and NaI). The ratio of these two weights is 5.52/1.54 = 3.58. It is also observed that 1 gram of chlorine reacts with 1.19 g of iodine. This ratio of 1.19 obeys the law because it is a simple fraction (1/3) of 3.58. (This is because it c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Law Of Multiple Proportions
In chemistry, the law of multiple proportions states that if two elements form more than one compound, then the ratios of the masses of the second element which combine with a fixed mass of the first element will always be ratios of small whole numbers. This law is also known as: ''Dalton's Law'', named after John Dalton, the chemist who first expressed it. For example, Dalton knew that the element carbon forms two oxides by combining with oxygen in different proportions. A fixed mass of carbon, say 100 grams, may react with 133 grams of oxygen to produce one oxide, or with 266 grams of oxygen to produce the other. The ratio of the masses of oxygen that can react with 100 grams of carbon is 266:133 = 2:1, a ratio of small whole numbers. Dalton interpreted this result in his atomic theory by proposing (correctly in this case) that the two oxides have one and two oxygen atoms respectively for each carbon atom. In modern notation the first is CO (carbon monoxide) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Law Of Constant Composition
In chemistry, the law of definite proportions, sometimes called Proust's law, or law of constant composition states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method of preparation. For example, oxygen makes up about 8/9 of the mass of any sample of pure water, while hydrogen makes up the remaining 1/9 of the mass: the mass of two elements in a compound are always in the same ratio. Along with the law of multiple proportions, the law of definite proportions forms the basis of stoichiometry. History The law of constant proportion was given by Joseph Proust in 1797. This observation was first made by the English theologian and chemist Joseph Priestley, and Antoine Lavoisier, a French nobleman and chemist centered on the process of combustion. The law of definite proportions might seem obvious to the modern chemist, inherent in the very definition of a chemical compound. At the end of the 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Law Of Definite Proportions
In chemistry, the law of definite proportions, sometimes called Proust's law, or law of constant composition states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method of preparation. For example, oxygen makes up about 8/9 of the mass of any sample of pure water, while hydrogen makes up the remaining 1/9 of the mass: the mass of two elements in a compound are always in the same ratio. Along with the law of multiple proportions, the law of definite proportions forms the basis of stoichiometry. History The law of constant proportion was given by Joseph Proust in 1797. This observation was first made by the English theologian and chemist Joseph Priestley, and Antoine Lavoisier, a French nobleman and chemist centered on the process of combustion. The law of definite proportions might seem obvious to the modern chemist, inherent in the very definition of a chemical compound. At the end of the 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reagent
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a substance ''consumed'' in the course of a chemical reaction. ''Solvents'', though involved in the reaction mechanism, are usually not called reactants. Similarly, ''catalysts'' are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates. Definitions Organic chemistry In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents. Analytical chemistry In analytical chemistry, a reagent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apocrypha
Apocrypha are works, usually written, of unknown authorship or of doubtful origin. The word ''apocryphal'' (ἀπόκρυφος) was first applied to writings which were kept secret because they were the vehicles of esoteric knowledge considered too profound or too sacred to be disclosed to anyone other than the initiated. ''Apocrypha'' was later applied to writings that were hidden not because of their divinity but because of their questionable value to the church. In general use, the word ''apocrypha'' has come to mean "false, spurious, bad, or heretical". Biblical apocrypha are a set of texts included in the Septuagint and the Latin Vulgate, but not in the Hebrew Bible. While Catholic tradition considers some of these texts to be deuterocanonical, and the Orthodox Churches consider them all to be canonical, Protestants consider them apocryphal, that is, non-canonical books that are useful for instruction. Luther's Bible placed them in a separate section in between the Old Test ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Testament
The New Testament grc, Ἡ Καινὴ Διαθήκη, transl. ; la, Novum Testamentum. (NT) is the second division of the Christian biblical canon. It discusses the teachings and person of Jesus, as well as events in first-century Christianity. The New Testament's background, the first division of the Christian Bible, is called the Old Testament, which is based primarily upon the Hebrew Bible; together they are regarded as sacred scripture by Christians. The New Testament is a collection of Christian texts originally written in the Koine Greek language, at different times by various authors. While the Old Testament canon varies somewhat between different Christian denominations, the 27-book canon of the New Testament has been almost universally recognized within Christianity since at least Late Antiquity. Thus, in almost all Christian traditions today, the New Testament consists of 27 books: * 4 canonical gospels (Matthew, Mark, Luke, and John) * The Acts of the Apostl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biblical Canon
A biblical canon is a set of texts (also called "books") which a particular Jewish or Christian religious community regards as part of the Bible. The English word ''canon'' comes from the Greek , meaning " rule" or "measuring stick". The use of the word "canon" to refer to a set of religious scriptures was first used by David Ruhnken, in the 18th century. Various biblical canons have developed through debate and agreement on the part of the religious authorities of their respective faiths and denominations. Some books, such as the Jewish–Christian gospels, have been excluded from various canons altogether, but many disputed books are considered to be biblical apocrypha or deuterocanonical by many, while some denominations may consider them fully canonical. Differences exist between the Hebrew Bible and Christian biblical canons, although the majority of manuscripts are shared in common. Different religious groups include different books in their biblical canons, in varying ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patriarch Nicephorus I Of Constantinople
Nikephoros I or Nicephorus I (c. 758 – 5 April 828) was a Byzantine writer and patriarch of Constantinople from 12 April 806 to 13 March 815. Life He was born in Constantinople as the son of Theodore and Eudokia, of a strictly Orthodox family, which had suffered from the earlier Iconoclasm. His father Theodore, one of the secretaries of Emperor Constantine V, had been scourged and banished to Nicaea for his zealous support of Iconodules, and the son inherited the religious convictions of the father. Nevertheless, he entered the service of the Empire, became cabinet secretary (''asekretis''), and under Irene took part in the synod of 787 as imperial commissioner. He then withdrew to one of the cloisters that he had founded on the eastern shore of the Bosporus, until he was appointed director of the largest home for the destitute in Constantinople c. 802. After the death of the Patriarch Tarasios of Constantinople, although still a layman, he was chosen patriarch by the wis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
