Search results
Results From The WOW.Com Content Network
[] = [] In order to find the half-life, we have to replace the concentration value for the initial concentration divided by 2: [] / = [] / and isolate the time: / = [] This t ½ formula indicates that the half-life for a zero order reaction depends on the initial concentration and the rate constant.
Here stands for concentration in molarity (mol · L −1), for time, and for the reaction rate constant. The half-life of a first-order reaction is often expressed as t 1/2 = 0.693/k (as ln(2)≈0.693).
Since the reaction rate determines the reaction timescale, the exact formula for the Damköhler number varies according to the rate law equation. For a general chemical reaction A → B following the Power law kinetics of n-th order, the Damköhler number for a convective flow system is defined as:
A more intuitive characteristic of exponential decay for many people is the time required for the decaying quantity to fall to one half of its initial value. (If N(t) is discrete, then this is the median life-time rather than the mean life-time.) This time is called the half-life, and often denoted by the symbol t 1/2. The half-life can be ...
C 0 is the initial concentration (t = 0) k e is the elimination rate constant; The relationship between the elimination rate constant and half-life is given by the following equation: = / Because ln 2 equals 0.693, the half-life is readily calculated from the elimination rate constant.
Using the Eyring equation, there is a straightforward relationship between ΔG ‡, first-order rate constants, and reaction half-life at a given temperature. At 298 K, a reaction with ΔG ‡ = 23 kcal/mol has a rate constant of k ≈ 8.4 × 10 −5 s −1 and a half life of t 1/2 ≈ 2.3 hours, figures that are often rounded to k ~ 10 −4 s ...
If one adds 1 litre of water to this solution, the salt concentration is reduced. The diluted solution still contains 10 grams of salt (0.171 moles of NaCl). Mathematically this relationship can be shown by equation: = where c 1 = initial concentration or molarity; V 1 = initial volume
where A and B are reactants C is a product a, b, and c are stoichiometric coefficients,. the reaction rate is often found to have the form: = [] [] Here is the reaction rate constant that depends on temperature, and [A] and [B] are the molar concentrations of substances A and B in moles per unit volume of solution, assuming the reaction is taking place throughout the volume of the ...