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To make a 100 ml solution of T 10 E 1 buffer, 1 ml of 1 M Tris base (pH 10–11) and 0.2 ml EDTA (0.5 M) are mixed and made up with double distilled water up to 100ml. Add microliter amounts of high molarity HCl to lower the pH to 8. Based on nuclease studies from the 1980s, the pH is usually adjusted to 7.5 for RNA and 8.0 for DNA.
In a typical preparation, 255 mL of a solution with 118 g/L HClO is slowly added with stirring to a solution of 40 g of NaOH in water 0 °C. Some sodium chloride precipitates and is removed by filtration. The solution is vacuum evaporated at 40–50 °C and 1–2 mmHg until the dihydrate crystallizes out. The crystals are vacuum-dried to ...
Tris (with HCl) has a slightly alkaline buffering capacity in the 7–9.2 range. The conjugate acid of Tris has a pK a of 8.07 at 25 °C. The pK a declines approximately 0.03 units per degree Celsius rise in temperature. This can lead to relatively dramatic pH shifts when there are shifts in solution temperature.
Alternatively, a solution of H[AuCl 4] can be produced by electrolysis of gold metal in hydrochloric acid: 2 Au(s) + 8 HCl(aq) → 2 H[AuCl 4](aq) + 3 H 2 (g) To prevent the deposition of gold on the cathode, the electrolysis is carried out in a cell equipped with a membrane. This method is used for refining gold.
A serial dilution is the step-wise dilution of a substance in solution, either by using a constant dilution factor, or by using a variable factor between dilutions. If the dilution factor at each step is constant, this results in a geometric progression of the concentration in a logarithmic fashion.
Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. [2] For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase : [3]
The solubility of a specific solute in a specific solvent is generally expressed as the concentration of a saturated solution of the two. [1] Any of the several ways of expressing concentration of solutions can be used, such as the mass, volume, or amount in moles of the solute for a specific mass, volume, or mole amount of the solvent or of the solution.
Speciation of ions refers to the changing concentration of varying forms of an ion as the pH of the solution changes. [1]The ratio of acid, AH and conjugate base, A −, concentrations varies as the difference between the pH and the pK a varies, in accordance with the Henderson-Hasselbalch equation.