Fundamental laws Flashcards
What is the Law of Conservation of mass? Who is its author?
Author: Antoine LAVOISIER
Law: In a chemical reaction, mass is neither created nor destroyed.
I.e. the sum of the masses of all products is equal to the sum of the mass of all reactants.
What is the Law of Definite Proportion / Law of Constant Composition? Who is its author?
Author: Joseph PROUST
Law: A given compound always contains exactly the same proportion of elements by mass.
I.e. copper (II) carbonate is always made of 5.3 parts of copper and 4 parts of oxygen for 1 part of carbon.
What is the law of Multiple Proportions? Who is its author?
When two elements form a series of compounds, the ratios of the masses of the second element that combine with 1 gram of the first element can always be reduced to small whole numbers;
(see pwt for example)
What is the Atomic Theory? Who is its author?
Each element is made up of tiny particles called atoms.
The atoms of a given element are identical; the atoms of different elements are different in some fundamental way or ways.
Chemical compounds are formed when atoms combine. A given compound always has the same relative numbers and types of atoms.
Chemical reactions involve reorganization of the atoms – changes in the way they are bound together. The atoms themselves are not changed in chemical reactions.
What is the fundamental law; Volume of Gases in Chemical Reactions?
Who is its author?
At the same conditions of temperature and pressure, the ratio of the volume of gases that react together can be reduced to a ratio of whole numbers. In addition, the ratio of the volume of each gas produced to the volume of each reactant can also be reduced to a ratio of whole numbers.
What is Avogadro’s Hypothesis? Who is its author?
At the same temperature and pressure, equal volumes of different gases contain the same number of particles.
Limitations: Avogadro’s hypothesis makes sense only if the distance between the particles in a gas is very great compared with the sizes of the particles. This works only at low pressures and high temperatures, and such gases are called “ideal gases” and they obey the “ideal gas law.” At low temperatures and/or high pressures, deviations from the ideal gas behaviour occur and then the gases are called “real gases” and they obey the “Van der Waals equation.”
