Symbol S_F
is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Published equation contexts
Why this formula appears here
When a reaction can plausibly form more than one product — partial versus complete oxidation, a straight-chain versus branched hydrocarbon, hydrogen versus oxygen evolution as a side reaction — “selectivity” names which pathway wins, and IUPAC defines it with no vocabulary that presumes anything about the catalyst’s intent: fractional selectivity for a given product is the extent-of-reaction rate toward that product divided by the sum of rates toward all products, = / , and relative selectivity between two products is simply the ratio of their two rates [ 2 ] . Selectivity is therefore a kinetic competition among simultaneous pathways, decided by which transition state…
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Symbol xi_i
x is an input to the expression that computes the quantity on the left.
Read this term in its guide →Symbol j
j appears in the bound of this sum. The bound states where the repeated operation starts, ends, or which values it includes.
Read this term in its guide →Symbol xi_j
x is an input to the expression that computes the quantity on the left.
Read this term in its guide →Starting index or lower bound: j
This label says where the repeated addition, multiplication, or accumulation starts. Read its value or condition together with the article’s description of the index.
Read this term in its guide →How to interpret it
Read it with the definitions, units, and assumptions supplied by the article.
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Published contexts (1)
A symbol can carry a different meaning in another article. Each occurrence keeps its own guide and term definitions.
Equation 3 · Chemistry
How Chemical Dynamics and Catalysis Actually Work
This equation states an equality: the expressions on both sides have the same value under the article’s assumptions.
When a reaction can plausibly form more than one product — partial versus complete oxidation, a straight-chain versus branched hydrocarbon, hydrogen versus oxygen evolution as a side reaction — “selectivity” names which pathway wins, and IUPAC defines it with no vocabulary that presumes anything about the catalyst’s intent: fractional selectivity for a given product is the extent-of-reaction rate toward that product divided by the sum of rates toward all products, = / , and relative selectivity between two products is simply the ratio of their two rates [ 2 ] . Selectivity is therefore a kinetic competition among simultaneous pathways, decided by which transition state…
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