"Text" is a predefined property that represents text of arbitrary length and is provided by Semantic MediaWiki. This property is pre-deployed (also known as special property) and comes with additional administrative privileges but can be used just like any other user-defined property.
D
meta +
DipropylSulfone +
a chemical compound consisting of a sulfone group bonded to two propyl groups +
dipropylsulfone +
meta +
Coulometry at an imposed, constant current in the electrochemical cell. Direct coulometry at controlled current is usually carried out in convective mass transfer mode. The end-point of the electrolysis, at which the current is stopped, must be determined either from the inflection point in the E–t curve or by using visual or objective end-point indi- cation, similar to volumetric methods. The total electric charge is calculated as the product of the constant current and time of electrolysis or can be measured directly using a coulometer. The advantage of this method is that the electric charge consumed during the electrode reaction is directly proportional to the electrolysis time. Care must be taken to avoid the potential region where another electrode reaction may occur. +
DirectCoulometryAtControlledCurrent +
directcoulometryatcontrolledcurrent +
Coulometry at a preselected constant potential of the working electrode. Direct coulometry at controlled potential is usually carried out in convective mass trans- fer mode using a large surface working electrode. Reference and auxiliary electrodes are placed in separate compartments. The total electric charge is obtained by integration of the I–t curve or can be measured directly using a coulometer. +
DirectCoulometryAtControlledPotential +
In principle, the end point at which I = 0, i.e. when the concentration of species under study becomes zero, can be reached only at infinite time. However, in practice, the electrolysis is stopped when the current has decayed to a few percent of the initial value and the charge passed at infinite time is calculated from a plot of charge Q(t) against time t. For a simple system under diffusion control Qt= Q∞[1 − exp(−DAt/Vδ)], where Q∞ = limt→∞Q(t) is the total charge passed at infinite time, D is the diffusion coefficient of the electroactive species, A the electrode area, δ the diffusion layer thickness, and V the volume of the solution. +
directcoulometryatcontrolledpotential +
DirectCurrent +
DirectCurrent +
Signal consisting of a constant electric current. +
directcurrent +
directcurrent +
electric current that flows in a constant direction, i.e. a current with a constant sign +