How to match pH meter electrode protection solution
Preparation of 3mol/L KCL solution for pH meter The pH electrode of the pH meter is protected by the protective solution in the sheath before use, in order to keep its original pH potential balance unchanged, in order to make the measurement more accurate. Here is the protective solution of the PH electrode, that is, a 3mol/L KCL solution. So you have to learn how to configure it yourself, so that the pH electrode is immersed in the protective solution, so that its activity can be quickly recovered, and it can be measured well. The following are the steps for preparing pH meter protection solution - 3mol/L KCL solution: 1. Calculation: KCL molar mass is 74.5g/moL, then KCL mass=3mol×74.5g/mol=223.5g; 2. Weighing: use analysis The balance weighs KCL=223.5g, pay attention to the use of the analytical balance; 3. Dissolve: dissolve it completely with 100ml of distilled water in a beaker, and stir with a glass rod; 4. Transfer, wash: transfer the dissolved solution into a 1000ml volumetric flask, Use a volumetric flask with a narrower mouth. Note: In order to prevent the solution from spilling, and do not let the solution flow down the bottle wall above the scale line, use a glass rod to drain. To ensure that as much as possible the solute is transferred into the volumetric flask, the beaker and glass rod should be washed two or three times with distilled water, and the solution after each wash is poured into the volumetric flask. Gently shake the volumetric flask to mix the solution well. (Drainage with a glass rod) Constant volume: When adding water to 2-3 cm close to the scale, use a plastic tip dropper to add distilled water to the scale. When setting the volume, pay attention to the tangent between the lowest part of the concave liquid level of the solution and the scale line, and the line of sight of the eyes is horizontal to the scale line, and cannot look down or look up, otherwise errors will be caused. 6. Shake well: The concentration of the solution after constant volume is not uniform, the stopper of the volumetric flask should be tightly plugged, the stopper should be pressed with the index finger, the bottom of the bottle should be supported with the finger of the other hand, and the volumetric flask should be inverted and shaken several times. to mix the solution evenly. 7. Shake the KCL solution after constant volume. Pour the prepared solution into the reagent bottle, cap the bottle, and label it. In this way, a 3mol/L KCL solution is prepared. The calibration buffer of the pH meter also has its configuration method, but most of them are bagged reagents with simple configuration, and these can also be purchased in the market.
