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The law of multiple proportions is one of the basic laws studied in chemistry. It along with the law of definite proportions has contributed to the understanding of stoichiometry in early days. The law was proposed by English chemist John Dalton in 1803, who is also known for his law of partial pressures. Dalton published the law in his book New System of Chemical Philosophy (Vol 1).
The law of definite proportions is also known as the law of definite composition or the law of constant composition, or simply Proust’s law. It is one of the basic laws in chemistry and a part of the laws of chemical combinations. In 1794, French chemist Joseph Proust proposed this law. That time the knowledge of chemical compound was not fully evolved, and he was opposed by many well-known chemists of that time. But later they were proven wrong. The law of definite proportions was later extended by John Dalton when Dalton proposed the law of multiple proportions.
The law of conservation of matter is a fundamental law in science. It is also known as the law of conservation of mass. The later is used in physics while the former in chemistry. It is one of the laws of chemical combinations in chemistry. The law has huge applications in chemistry, physics, and engineering. In a closed system, the exchange of matter is restricted across its boundaries. So, there is no matter entering the system or leaving the system. Thus, the flow of matter in and out of the system is zero. These statements are true only for a closed system with no nuclear change. We can apply the law to systems which are subjected to physical and chemical changes, not nuclear changes. This will be better understood as we go through the article.
The ideal gas constant is also known as the universal gas constant or the molar gas constant or simply the gas constant. It is a very important constant in chemistry and physics. It is denoted as R. The dimension of the gas constant is expressed in energy per unit mole per unit temperature. The value of the gas constant in SI unit is 8.314 J mol−1 K−1. The gas constant has the same unit as of entropy and molar heat capacity.
Ideal gas equation is PV = nRT. This equation can easily be derived from the combination of Boyle’s law, Charles’s law, and Avogadro’s law. But here, we will derive the equation from the kinetic theory of gases. The kinetic theory of gases is a very important theory which relates macroscopic quantities like pressure to microscopic quantities like the velocity of gas molecules. This equation is applicable only for ideal gases, but be approximated for real gas under some conditions.
The Ideal gas law is also known as general gas law. As the name states the law is applicable under the ideal conditions, not to real gases. The law correlates the pressure, volume, temperature, and amount of gas. It was first formulated by French physicist Émile Clapeyron in 1834.
The Boltzmann constant is a very important constant in physics and chemistry. The constant relates the average kinetic energy of molecules of a gas with thermodynamic temperature. The Boltzmann constant is denoted as kB or k. The dimension of the Boltzmann constant is energy per thermodynamic temperature. The SI unit is J K−1, which is the same as of entropy. The value of the Boltzmann constant is 1.380 649 × 10−23 J K−1.
Graham's law of diffusion (or Graham's law of effusion) is a law that expresses the relationship between the rate of diffusion or effusion to molar masses of particles. This empirical law was stated by Scottish chemist Thomas Graham in 1848. He established the relationship through experiments.
Dalton's law is also known as the law of partial pressure or Gibbs-Dalton law (rarely). The law describes the relationship between the total pressure of a mixture of non-reacting ideal gases and the partial pressures of each individual component. Dalton's law is valid for ideal gases. The law is similar to Amagat's law of additive volumes.
An amagat is a unit of number density. It is similar to Loschmidt constant which is the molecular density quoted at STP (T = 273.15 K, P = 1 atm). 1 amagat is defined as the number of molecules of an ideal gas per unit volume at STP. 1 amagat is equivalent to Loschmidt constant. The symbol used for amagat is amg or Am (rarely). It is a non-SI unit.
The number is named after Émile Hilaire Amagat. He was a French physicist and also known for Amagat’s law of additive volume.
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