Constant proportions, law

These laws played a significant part in Dalton s development of his atomic theory (1808). See conservation of mass, law of constant proportions, law of equivalent proportions, law of multiple proportions, law of. 

Constant proportions, law of 63, 66 Continuity of the gaseous and Uquld statesof matter, 78 Oontnietion aid expansion of vmter, 224,228... 

In this context, k is called the decay constant. The law tells us that the activity of a radioactive sample is proportional to the number of atoms in the sample. As we saw in Section 13.4, a first-order rate law implies an exponential decay. It follows that the number N of nuclei remaining after a time t is given by... 

The Law of Constant Proportion" -- The same chemical compound always contains the same elements, and there is a constant ratio between the weights of the constituent elements present. 

Berthollet (1748-1822) denied the tmth of the law of constant proportion, and a controversy ensued between this chemist and Proust (1755-1826), who undertook a research to settle the question, the results of which were in entire agreement with the law, and were regarded as completely substantiating it. 

Lattice Points positions in a unit cell occupied by atom, molecules, or ions Law of Definite Proportion law that states that different samples of the same compound always contain elemental mass percentages that are constant Law of Mass Action mathematical expression based on the ratio between products and reactants at equilibrium, an equation to determine the equilibrium rate constant Law of Multiple Proportions law that states when two elements combine to form more than one compound that the mass of one element compared to the fixed mass of... 

Boyle-Mariotte s Law, states that the product of volume and pressure is constant, pv=k, at const temp. Another gas law states that the vol of a gas at 0°C increases with each °C by 1/273, provided the pressure is constant, and that the pressure increases with each °C, provided the volume remains constant. This law is known as Charles1 Law, because it was formulated by French chemist Jacques Charles (1746-1822) (Ref 1, p 186-R). The so-called Dalton s Law, formulated by John Dalton (1766—1844), Engl chemist physicist, founder of atomic theory, states that the pressure of a gas mixture equals the sum of the partial pressures of the constituent gases (Ref 1, p 252-R). The so-called Gay-Lussoc s Law states that when gases interact, the volumes of the reacting gases and the volume of the reaction product are in simple, proportions and can be expressed by whole numbers. This law was formulated by a French chemist and physicist Gay-Lussac(qv) Refs 1) Hackh s Diet (1944), pp 89-R, 141-R,... 

The proportions of the constituents of air vary a little in different localities, but even this small variation is not found with pure chemical compounds—law of constant proportions. Hence, not all the nitrogen and oxygen are combined. 

Again we can easily calculate the full crossover. As an example Fig. 14.3 shows the scaling function V/s as function of s in the excluded volume limit. In unrenormalized tree approximation this ratio would be a constant proportional to the second virial coefficient. In renormalized theory we see a pronounced variation which rapidly approaches the asymptotic power law. 

The validity of a first-order decay law over time for the activity of enzymes according to Eq. (2.19), with [E]t and [E]0 as the active enzyme concentration at time t or 0, respectively, and kd as the deactivation rate constant, is based on the suitability of thinking of the deactivation process of enzymes in terms of Boltzmann statistics. These statistics cause a certain number of active protein molecules to deactivate momentarily with a rate constant proportional to the amount of active protein [ for evidence for such a catastrophic decomposition, see Craig (1996)]. 

The first strides after recognition of mass conservation led to the formulation of several phenomenological laws of chemical composition, such as the laws of constant proportions, multiple proportions and eguivalent proportions, found to be obeyed during interaction between chemical substances. These laws served to catalogue and systematize a large body of empirical... 

HISTORICAL REMARKS. THE LAWS OF CONSTANT PROPORTIONS, SIMPLE MULTIPLE PROPORTIONS, AND COMBINING WEIGHTS... 

Three laws of stoichiometry may now be considered The Laio of Constant Proportions, The Law of Simple Multiple Proportions, and The Law of Combining V/eights. These were originally empirical laws, based upon experiment. At the time that the laws were formulated it was seen that the atomic theory provides a simple explanation of them and although the laws do not require that the atomic theory be true most chemists accepted the theory as providing the simplest explanation of chemical weight relations. 

The Law of Constant Proportions. Different samples of a substance contain elements iti the same propotlions. 

The law of constant proportions was enunciated by the French chemist Joseph Louis Proust (1754-1826) in 1799. For several years it was attacked vigorously by Claude Louis Bertholet (1748-1822), who contended that the composition of the compound depended on the way in which it was prepared. Proust defended the law by pointing out that the materials described by Bertholet as exceptions were mixtures (of different lead oxides, of mercurous salts and mercuric salts, etc.) or solutions. Accurate data showing constancy of composition of the substances investigated to 1 part in 100,000 were first reported by the Belgian chemist J. S. Stas in 1865. 

Historical development the laws of constant proportions, simple multiple proportions, and combining weights. 

When the feedstock contains constant proportions of reactive impurities, the rate of decline may also depend on the concentration of the main reactant, e.g., for a power law rate... 

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