Multiple proportions

The oxides of nitrogen played an important role in exemplifying Dalton s law of multiple proportions which led up to the formulation of his atomic theory (1803-8), and they still pose some fascinating problems in bonding theory. Their formulae, molecular structure, and physical appearance are briefly summarized in Table 11.7 and each compound is discussed in turn in the following sections. 

The law of multiple proportions This law, formulated by Dalton himself, was crucial to establishing atomic theory. It applies to situations in which two elements form more than one compound. The law states that in these compounds. the masses of one element that combine with a fixed mass of the second element are in a rath of small whole numbers. 

Which, if any, of the following results for the mass ofhydrogen in compound C follows the law of multiple proportions ... 

Multiple equilibria, rule of A rule stating that if Equation 1 + Equation 2 = Equation 3, then K3 = K1X K2,370,439 Multiple proportions, 27... 

Stoichiometry (from the Greek stoikeion—element) is the practical application of the law of multiple proportions. The stoichiometric equation for a chemical reaction states unambiguously the number of molecules of the reactants and products that take part from which the quantities can be calculated. The equation must balance. 

Regarding the "ancestral lineage" on the poster, Democritus, of course, takes first place. Then comes John Dalton (1766-1844), an unassuming religious person whose broad scientific knowledge was self-taught. With his law of multiple proportions of the elements in their different chemical compounds, he rightfully saw indirect proof for the existence of atoms. He represented them as... 

The law of multiple proportions states that when two different compounds are formed from the same elements, the ratio of masses of one element in the two compounds for a given mass of any other element is a small whole number. 

Dalton argued that these laws are entirely reasonable if the elements are composed of atoms. For example, the reason that mass is neither gained nor lost in a chemical reaction is that the atoms merely change partners with each other they do not appear or disappear. The constant composition of compounds stems from the fact that the compounds consist of a definite ratio of atoms, each with a definite mass. The law of multiple proportions is due to the fact that different numbers of atoms of... 

Show that these compounds obey the law of multiple proportions. 

The ratio of 1.50 1 is equal to the ratio 3 2, and the law of multiple proportions is satisfied. Note that the ratio of masses of iron to oxygen is not necessarily a ratio of small integers the ratio of mass of oxygen in one compound to mass of oxygen in the other compound is what must be in the small integer ratio. 

Chemists do not use the law of multiple proportions in their everyday work. Why was this law... 

Ans. The compounds have different ratios of hydrogen to oxygen atoms, and thus different mass ratios. The law of definite proportions applies to each compound individually, not to the two different compounds. H20 and H202 each follow the law of definite proportions (and together they also follow the law of multiple proportions). 

The ratio of masses of oxygen in the two compounds (for a given mass of Cu) is the ratio of small integers, as required by the law of multiple proportions. The ratio of mass of copper to mass of oxygen is not integral. 

The development of chemistry itself has progressed significantly by analytical findings over several centuries. Fundamental knowledge of general chemistry is based on analytical studies, the laws of simple and multiple proportions as well as the law of mass action. Most of the chemical elements have been discovered by the application of analytical chemistry, at first by means of chemical methods, but in the last 150 years mainly by physical methods. Especially spectacular were the spectroscopic discoveries of rubidium and caesium by Bunsen and Kirchhoff, indium by Reich and Richter, helium by Janssen, Lockyer, and Frankland, and rhenium by Noddack and Tacke. Also, nuclear fission became evident as Hahn and Strassmann carefully analyzed the products of neutron-bombarded uranium. 

This question is similar to question 10 in that two elements, phosphorus and chlorine in this case, have combined to give two different compounds. This time, however, different masses have been used for both of the elements in the second reaction. To see if the Law of Multiple Proportions is being followed, the mass of one of the two elements must be set to the same value in both reactions. This can be achieved by dividing the masses of both phosphorus and chlorine in reaction 2 by 2.500 ... 

These results are consistent with the Law of Multiple Proportions because the masses of hydrogen in the three compounds end up in a ratio of small whole numbers when the mass of nitrogen in all three compounds is normalized to a simple value (1.000 g here). 

Background Many elements combine with oxygen or other nonmetals in various ratios i.e. FeO, Fe203, Fe304. This phenomenon demonstrates the Law of Multiple Proportions. In this experiment, you will analyze the ratios in which lead and chlorine can combine and from the data provided, be able to determine the empirical formulas of the compounds produced. 

There are rules that guide the way in which the various elements can combine, which were most elegantly expressed by John Dalton (1766-1844) in his New System of Chemical Philosophy, published in three volumes between 1808 and 1827. Here he explained the theory of the Law of Multiple Proportions, which formed the basis of his atomic theory, as follows ... 

The Law of Multiple Proportions" -- If two substances combine chemically in more than one proportion, the weights of the one which combine with a given weight of the other, stand in a simple rational ratio to one another. 

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