Jacques Charles - Wikipedia
The empirical evidence presented by Gay-Lussac of gases combining in simple in order to reduce to two oxides all those which the same metal sometimes presents. .. According to Boyle's law, the volume of a gas at constant temperature is . Its name until (oxymuriatic acid), however, reflected the belief that it did. derivation.6 In other words, Berzelius concluded from Gay-Lussac's law that equal volumes of difference, one must assume a different mode of combination between their ele- ments."'2 may have represented nothing more than the revelation for the first time of convic- . gration of his belief in the EVEN hypothesis. After the discovery of Gay-Lussac's law (that gases combine together in simple increasing amount of quantitative data, chemists lost faith in both the of chemistry was Berthollet and his mistake, the denial of the law of constant composition, .. any vertical rise (which was proportional to temperature), represented the.
The end result was that Pythagoreus was exiled to Italy where he lived until 80 and continued teaching his following.
We also assume that the rules that describe the order of nature are basically simple - meaning that humans can eventually discover. Objective Reality Objective reality has to do with the idea that events may be different depending upon one's point of view. At some level our interpretation depends upon our view but the description of the actual things that happen during an event are held to be the same independent of the beliefs or interpretation of the observers.
In science, if one person demonstrates a principle, a competent observer should be able to repeat the demonstration and get the same results. We have to be careful to distinguish between what happened and our interpretation of what happened. There is a certain skill and experience needed to determine what is the objective reality of an event and what is our interpretation of the event.
The following demonstration will help to illustrate this point. Demonstration This is an attempt to describe the objective reality of the demonstration.
The professor lights a Bunsen burner and places it under a long pipe. A thin polyethelene dry cleaners bag with a wide mouth is placed over the top of the long pipe. The bag begins to swell up until it appears full and stands up straight. When it is released, it rises toward the ceiling of the room.
It then tips, collapses together and slowly falls back to the table or floor. That is what we try to describe in a way that that all competent observers would agree upon. That is the objective reality. Why did it happen? It calls for an explanation. Nature of an Explanation Animistic: Animism is the belief that natural objects are alive and have souls, so one possible explanation is that the bag rose because it wanted to escape the heat. This is a common explanation, particularly for children.
To them things are alive, and have a will of their own. The bag being able to rise is no more surprising than the child is able to walk to the door.
Scientific law - Wikipedia
The animistic world is a chaotic world. All natural objects behave according to their whims. You would not be able to expect to tell what the bag will do next any better than you can tell what the childchangeable creature that he is, will want to do in five minutes. Magic is the art of producing effects or controlling events by charms, spells, and rituals. This is great if you are in the sorcerer's club. The explanation of what happened would then be "The lecturer is a wizard, who knows a secret trick.
A magician can make the event happen by the use of some incantation, special formula, or sleight of hand. The teacher knows them and is able to astonish his audience. The image of the scientist-as-parlor magician, capable of doing all sorts of tricks is still current. A century or more in the past, it was common for scientists to earn their living giving lecture demonstrations with lots of sparks, flames, and chemicals foaming.
The idea that one can control things by learning the right secrets is very powerful and appealing. Supernatural things are those caused by supposed forces beyond the normal, known forces of nature. The bag rose because " a miracle occurred". This could be because the gods, God, or some Being or Power has intervened in the natural order of things and thus caused events to occur that would not ordinarily.
Theism is the belief in a God who is the creator and ruler of the Universe. The bag rises because "It is the will of God.
If there are Natural Laws obeyed by all nature, then it is He who established them.
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And if events take place in violation of these laws, it is He alone who is responsible. In the end, all actions that take place do so because He willed them, and direct or indirectly made them happen. An omnipotent God could either personally intervene in everything or ordain a system that would do them. Many sincere people, including scientists, hold these or similar beliefs. Generally, scientists operate on the assumption that individual intervention is not the rule but that all things follow Natural Laws.
The scientist seeks to find those laws. From the typical scientist's point of view appealing to constant intervention explains too little because it explains too much - namely everything. If everything is due to Divine will, and if that will is beyond human knowing, then we know nothing at all. If, on the other hand, the deity originally established the natural system, and the laws of nature, however, established are now universally obeyed, then it is the goal of the scientist for determine those laws.
It is a generally unspoken tenet of science that such laws do exist, and that they are basically simple. Teological means directed towards a definite end, or having an ultimate purpose. The bag rises because "It is the nature of warm air to rise. I have already proved that oxygenated muriatic gas is composed of parts of muriatic gas and of oxygen gas. Admitting that the apparent contraction of the two gases is half the whole volume, we find 2.
I have also assured myself by several experiments that the proportions of its elements are such that it forms neutral salts with the metals. For example, if we pass oxygenated muriatic gas over copper, there is formed a slightly acid green muriate, and a little oxide of copper is precipitated, because the salt cannot be obtained perfectly neutral. It follows from this that in all the muriates, as in oxygenated muriatic acid, the acid reduced to volume is thrice the oxygen.
It would be the same for carbonates and fluorides, the acids of which have for equal volumes the same saturation capacity as muriatic acid. Only very slight differences exist between the densities of compounds obtained by calculation and those given by experiment, and it is probable that, on undertaking new researches, we shall see them vanish entirely.
Recalling the great law of chemical affinity, that every combination involves an approximation of the elementary molecules, it is difficult to conceive why carbonic oxide gas should be lighter than oxygen. Berthollet to assume the existence of hydrogen in this gas, and thus explain its low density. But it seems to me that the difficulty arises from supposing that the approximation of the elementary molecules is represented in gases by the diminution of volume which they suffer on combination.
This supposition is not always true, and we might cite several gaseous combinations, the constituent molecules of which would be brought very close together, although there is not only no diminution of volume, but even a dilation. Such, for example, is nitrous gas, whether we consider it as being formed directly from nitrogen and oxygen, or from nitrous oxide and oxygen.
In the first case, there is no diminution of volume; and in the second, there would be dilation, for parts of nitrous oxide and 50 of oxygen would produce of nitrous gas. Nevertheless, if we admitted an immediate relation between the condensation of the elements and the condensation of volume, we should conclude, contrary to experiment, that there is no condensation.
Otherwise it would be necessary to suppose that if carbon were in the gaseous state it would combine in equal volumes or in any other proportion with oxygen, and that the apparent condensation would then be equal to the whole volume of the gaseous carbon.
But if we make this supposition for carbonic acid, we may also make it for carbonic oxide, by assuming, for instance, that parts of the gaseous carbon would produce parts of the gas on combining with 50 parts of oxygen. However it may stand with these suppositions, which only serve to make it conceivable that oxygen can produce a compound lighter than itself by combining with a solid substance, we must admit, as a truth founded on a great number of observations, that the condensation of the molecules of two combining substances, in particular of two gases, has no immediate relation to the condensation of volume, since we often see that whilst one is very great the other is very small or even nil.
According to Dalton's ingenious idea, that combinations are formed from atom to atom, the various compounds which two substances can form would be produced by the union of one molecule of the one with one molecule of the other, or with two, or with a greater number, but always without intermediate compounds.
Thomson has found that super-oxalate of potash contains twice as much acid as is necessary to saturate the alkali; and Wollaston, that the sub-carbonate of potash contains, on the other hand, twice as much alkali as is necessary to saturate the acid. The numerous results I have brought forward in this Memoir are also very favorable to the theory. Berthollet, who thinks that combinations are made continuously, cites in proof of his opinion the acid sulphates, glass alloys, mixtures of various liquids,--all of which are compounds with very variable proportions, and he insists principally on the identity of the force which produces chemical compounds and solutions.
We must first of all admit, with M. Berthollet, that chemical action is exercised indefinitely in a continuous manner between the molecules of substances, whatever their number and ratio may be, and that in general we can obtain compounds with very variable proportions.
But then we must admit at the same time that,--apart from insolubility, cohesion, and elasticity, which tend to produce compounds in fixed proportions,--chemical action is exerted more powerfully when the elements are in simple ratios or in multiple proportions among themselves, and that compounds are thus produced which separate out more easily. In this way we reconcile the two opinions, and maintain the great chemical law, that whenever two substances are in presence of each other they act in their sphere of activity according to their masses, and give rise in general to compounds with very variable proportions, unless these proportions are determined by special circumstances.1.3 The gas laws (Boyle's, Charles', Gay-Lussac's, combined gas law)
Conclusion I have shown in this Memoir that the compounds of gaseous substances with each other are always formed in very simple ratios, so that representing one of the terms by unity, the other is 1, or 2, or at most 3. These ratios by volume are not observed with solid or liquid substances, nor when we consider weights, and they form a new proof that it is only in the gaseous state that substances are in the same circumstances and obey regular laws.
It is remarkable to see that ammonia gas neutralizes exactly its own volume of gaseous acids; and it is probable that if all acids and alkalies were in the elastic state, they would all combine in equal volumes to produce neutral salts. The capacity of saturation of acids and alkalies measured by volume would then be the same, and this might perhaps be the true manner of determining it.
The apparent contraction of volume suffered by gases on combination is also very simply related to the volume of one of them, and this property likewise is peculiar to gaseous substances. According to Boyle's law, the volume of a gas at constant temperature is inversely proportional to its pressure: Furthermore, the proportionality constant was the same for every gas.
The result is that a given volume of any gas subjected to a given compression pressure increase will result in the same change of volume. This regular behavior of gases is contrasted with that of solids and liquids: Solids and liquids also expand upon heating, but each to a different extent.
That is, many properties of gases are regular, and are either the same in different gases or they vary in a fairly simple way with fundamental properties like mass. Properties of solids and liquids tend to be not nearly so regular.
After giving some examples of the regular behavior of gases, he correctly speculates that the details of cohesion in solids and liquids differ from substance to substance, and in the absence of that cohesion i. The philosopher Immanuel Kant considered chemistry to be incapable of the application of mathematics [Kant ]. Kant also classed chemistry as "nothing more than a systematic art or experimental doctrine, but never science proper.
InRichter formulated law of definite proportions and idea of associating combining masses equivalents to reacting substances. That is the question Gay-Lussac poses. At this time, examples were already known of more than one compound being formed from the same two elements in different compositions.
For example, there are two distinct compounds of carbon and oxygen, two different gases with different properties. Given the existence of multiple compounds of the same elements, is there a relationship of the compositions combining proportions in these compounds?
Joseph-Louis Proust ; see portrait at the Edgar Fahs Smith collection, University of Pennsylvania believed that there were only two combining proportions possible for any pair of elements [e. Proust ]; Claude-Louis Berthollet ; see portrait at the Edgar Fahs Smith collection, University of Pennsylvania believed that combining proportions between two elements was as a rule variable between upper and lower limits; and Dalton [ Dalton ] believed that there were only a few though perhaps more than two discrete combining proportions.
By the way, Proust was not the first to pursue this question; Richter had preceded him note 4. Consider the following example.
Suppose as Dalton did that carbon and oxygen form two different compounds, one consisting of an oxygen atom bound to a carbon atom and the other consisting of two oxygen atoms bound to a carbon atom; suppose further that the mass of a carbon atom is 12 and that of an oxygen atom Each of these compounds has a definite ratio of oxygen mass to carbon mass, namely It only makes sense to speak of whole numbers of atoms, so there is no possibility of intermediate mass ratios--at least in compounds that have only one carbon atom.
The third edition of Thomson's System of Chemistry [Thomson ] contains a description of Dalton's views. Berthollet included some critical remarks on Dalton's ideas in his introduction to a French edition of Thomson's book.
Indeed, the results Gay-Lussac presents support the hypothesis of definite proportions and Dalton's atomic hypothesis. Interestingly, though, Gay-Lussac's attitude in this paragraph seems either neutral or inclined to disbelieve Berthollet's opponents.
The early 19th century, however, was still a time of generalists rather than specialists in science. Notes will explain some of the reactions in modern notation and the modern names and formulas of the compounds.
What is important, however, is not so much the identity of the compounds involved in these reactions for indeed, Gay-Lussac did not know the formulas of many of them, and did not report the quantities of product formedbut the fact that in all the reactions the gases combined in simple ratios by volume.
That is to say for example one liter of one reactant with one, two, or three liters of another. Consideration of combining masses led to ratios not nearly as simple. In the first example given, that of water, Gay-Lussac means although does not say so explicitly that water contains parts of hydrogen by volume for every parts of oxygen. The formula for ammonia is NH3. Boyle's Law for volume and gas pressure The particle theory of gas pressure was explained in Part 1 so this section concentrates on the gas law calculations involving pressure and volume.
Boyle's Law states that for given mass of gas at a constant temperature oC or Kthe product of the pressure multiplied by the volume is a constant.
At lower temperatures the volume and pressure values are lower see next section. You can use any volume or pressure units you like as long as both p's and both V's have the same units. Using particle theory and simple arithmetical values to explain Boyles Law. If a gas is compressed to half its original volume the concentration or density of the gas is doubled.
Therefore there will be twice as many collisions with the surface causing twice the impact effect i. If the volume of a gas is increased by a factor of three, the concentration is reduced by the same factor, so the chance of particle collision with the container walls is similarly reduced, so the pressure decreases by a factor of three. Because the internal pressure in the cylinder is so much greater than the external pressure, on fitting a valve, a large volume of gas can be released to flow slowly under controlled conditions for a patients respiration.