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When heat is removed and the temperature decreases, the reaction shifts to the left and the flask turns colorless due to an increase in N 2 O 4: again, according to Le Chatelier's principle. The effect of changing the temperature in the equilibrium can be made clear by 1) incorporating heat as either a reactant or a product, and 2) assuming ...
Henry Louis Le Chatelier [1] (French pronunciation: [ɑ̃ʁi lwi lə ʃɑtəlje]; 8 October 1850 – 17 September 1936) was a French chemist of the late 19th and early 20th centuries. He devised Le Chatelier's principle , used by chemists and chemical engineers to predict the effect a changing condition has on a system in chemical equilibrium .
Since the reaction is exothermic, the equilibrium of the reaction shifts at lower temperatures to the ammonia side. Furthermore, four volumetric units of the raw materials produce two volumetric units of ammonia. According to Le Chatelier's principle, higher pressure favours ammonia.
The contact process is a method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum was originally used as the catalyst for this reaction; however, because it is susceptible to reacting with arsenic impurities in the sulfur feedstock, vanadium(V) oxide (V 2 O 5) has since been preferred.
(The heat change at constant pressure is called the enthalpy change; in this case the widely tabulated enthalpies of formation are used.) A related term is the heat of combustion , which is the chemical energy released due to a combustion reaction and of interest in the study of fuels .
(a) Le Chatelier's principle also states that when there is an external constraint on a system, a behavioural shift in the system occurs so as to annul the effect of that change. (b) Where a shock initially induces positive feedback (such as thermal runaway), the new equilibrium can be far from the old one, and can take a long time to reach.
According to Le Chatelier's principle, the addition of acetate ions from sodium acetate will suppress the ionization of acetic acid and shift its equilibrium to the left. Thus the percent dissociation of the acetic acid will decrease, and the pH of the solution will increase.
According to the thermal flame theory of Ernest-François Mallard and Le Chatelier, the un-stretched laminar flame speed is dependent on only three properties of a chemical mixture: the thermal diffusivity of the mixture, the reaction rate of the mixture and the temperature through the flame zone: