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Fick's first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative), or in simplistic terms the concept that a solute will move from a region of high concentration to a region of low ...
This unequal distribution results in a concentration gradient that drives the dispersion of particles in the medium so that the concentration is constant across the entire bulk. With respect to convection, variations in velocity between flow paths in the bulk facilitate the distribution of the dispersed material into the medium.
The diluted material must be thoroughly mixed to achieve the true dilution. For example, in a solution with a 1:5 dilution ratio, entails combining 1 unit volume of solute (the material to be diluted) with 5 unit volumes of the solvent to give 6 total units of total volume. In photographic development, dilutions are normally given in a '1+x ...
Therefore, the "net" movement of oxygen molecules (the difference between the number of molecules either entering or leaving the cell) is into the cell. In other words, there is a net movement of oxygen molecules down the concentration gradient. In astronomy, atomic diffusion is used to model the stellar atmospheres of chemically peculiar stars.
For example, if there are 10 grams of salt (the solute) dissolved in 1 litre of water (the solvent), this solution has a certain salt concentration . 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).
For example, concentration gradients in ethanol solutions in water move 1 μm diameter colloidal particles with diffusiophoretic velocities of order 0.1 to 1 μm/s, the movement is towards regions of the solution with lower ethanol concentration (and so higher water concentration). [6]
The process of osmosis over a semipermeable membrane.The blue dots represent particles driving the osmotic gradient. Osmosis (/ ɒ z ˈ m oʊ s ɪ s /, US also / ɒ s-/) [1] is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential ...
In thermodynamics, an activity coefficient is a factor used to account for deviation of a mixture of chemical substances from ideal behaviour. [1] In an ideal mixture, the microscopic interactions between each pair of chemical species are the same (or macroscopically equivalent, the enthalpy change of solution and volume variation in mixing is zero) and, as a result, properties of the mixtures ...