Tag Archive | Stoichiometry
Theoretical and Excess Air
Stoichiometric or Theoretical Combustion is the ideal combustion process where fuel is burned completely. With unburned components in the exhaust gas, such as C, H2, CO, the combustion process is uncompleted and not stoichiometric. The combustion process can be expressed as: [C + H (fuel)] + [O2 + N2 (Air)] -> (Combustion Process) -> [CO2 + H2O + […]
Extent of reaction
What is the extent of reaction? The extend of reaction are the coefficient called “Xi” (ξ). This sign is added to the coefficients of a molecular balanced equation. Example: If the combustion of propane is used in a mass balance problem the extent of reaction would be: Equation: C3H8 + 5O2 = 4H20 + 3C02 […]
Multiple Reactions,Yield and Selectivity
The terms Yield and Selectivity are used to describe the degree to which a desired reaction predominates over competing side reactions. Yield = moles of desired product formed/moles that would have been formed if there no side reactions and the limiting reactant had reacted completely Selectivity = moles of desired product formed/moles of undesired product […]
Limiting/Excess Reactants, Fractional Conversion and Extent of Reaction
The reactant that would run out before the reaction proceeded to completion is called the limiting reactant, and the other reactants are termed excess reactants. The fractional excess of the reactant is the ratio of the excess to the stoichiometric requirements. Fractional excess of A =[ (moles A)feed – (moles A)stoich]/(moles A)stoich The extent of […]
Stoichiometry
The theory of the proportions in which chemical species combine with one another. General rules for balancing: Write the unbalanced equation, including the correct formulas, for all reactants and products. Compare the number of atoms on the reactants and product(s) sides. Balance the elements by changing the number of molecules or ions with coefficients. Do not change the […]
Mass Balance Elements 