What is ph. PH (acidity) of blood: what is it, the norm in a blood test, how it is regulated when it changes. Adjusting the pH of the Nutrient Solution
When controlling the production of food concentrates, acidity is one of the main indicators characterizing the good quality of raw materials and finished products. Acidity is also one of the main factors that judge the direction of the biochemical and physico-chemical processes of food concentrate and vegetable drying production.
In the practice of control, the acidity is determined by the total, or titratable, and active, i.e. concentration of hydrogen ions - pH (psh).
Determination of total acidity
By total acidity is meant the content in the product of all acids and substances that react with alkali. Total acidity is expressed in the following quantities:
in percent by weight (weight) of any acid prevailing in this product (lactic, citric, malic, etc.);
in "degrees", i.e. in milliliters 1 n. alkali used to neutralize acidic compounds in 100 g of the product.
To express the acidity in weight percent of a certain acid, the number of milliliters is 0.1 N. alkali spent on the neutralization of acidic compounds in 100 g of the product is multiplied by the milliequivalent of the corresponding acid. The total acidity can be determined by titration with an alkali solution of aqueous solutions of the product in the presence of an indicator until its color changes or potentiometrically by electrometric titration.
Determination of acidity by titration
The acidity of the product by this method is determined in aqueous extracts of the studied products or by "talker".
In aqueous extracts, acidity is determined as follows. Depending on the nature of the investigated product and the expected acidity, a sample of the crushed product is taken in an amount of approximately 10 g (weighing accuracy up to 0.01 g). The sample is transferred to a 250 ml flask, poured into 200 ml of distilled water and infused for 30 minutes with frequent shaking. The contents of the flask were made up to the mark with distilled water, mixed well and filtered through a paper filter into a dry flask. Pipette 20-25 ml of the filtrate, transfer to a conical flask and titrate with 0.1 N. alkali solution in the presence of 3-5 drops of phenolphthalein until pink coloration. If the extracts are colored, then they are diluted 2-3 times with distilled water.
Acidity is calculated by the formula
where V is the amount of exactly 0.1 n. alkali used for titration, ml; K is the conversion factor for the corresponding acid. For lactic acid K - 0.0090, citric acid - 0.0064, malic acid - 0.0067, tartaric acid - 0.0075, acetic acid - 0.0060; g - sample of the product under study, g; V1 is the amount of filtrate taken for titration, ml.
When determining acidity by “talker”, a 5 g sample of the crushed product, taken with an accuracy of 0.01 g, is transferred into a conical flask with a capacity of 150–250 ml, into which 30–40 ml of distilled water is first poured. The contents of the flask are shaken for 2-3 minutes until the lumps of the product completely disappear. Small particles adhering to the walls of the flask are washed off with distilled water, five drops of a 1% solution of phenolphthalein are added to the masher and titrated with 0.1 N. alkali solution. Titration is carried out slowly (especially at the end of the reaction), with constant thorough shaking of the contents of the flask, until a bright pink color appears, which does not disappear within 1 min.
Acidity, expressed in degrees per 100 g of products (x), is calculated by the formula
where V is the amount of 0.1 n. alkali solution used for titration, ml; 20 - conversion factor per 100 g of products; 10 - conversion factor for 1 n. alkali solution.
The discrepancy between the results of parallel determinations should not exceed 0.5°. The method of electrometric titration is used to determine the acidity of intensely colored or cloudy solutions.
Determination of acidity by electrometric titration
It is based on determining the electrical conductivity of the test solution when it is titrated with an alkali solution. In the circuit of a galvanic cell consisting of two quinhydrone electrodes, a potential difference arises when one of the electrodes is immersed in a standard solution with a neutral reaction, and the other in the test solution. When the test solution is titrated with an alkali solution, the potential difference decreases. Upon reaching the neutral point, the potential difference is zero, the current in the circuit disappears, the potential of the indicator electrode is equal to the potential of the reference electrode. The absence of current is determined by the galvanometer of the galvanic cell included in the circuit.
For electrometric titration, a special installation or devices for measuring pH (psh) are used: IM-2M, LP-58 (Fig. 16, a), LPU-01 (Fig. 16, b), etc. The scheme of the special installation is shown in fig. 17. This apparatus consists of a conical flask with a capacity of 250-300 ml, in which a stopper with three holes is inserted. A glass tube with a tap 1 is inserted into one hole (tube diameter 0.8-1 cm, length 15-20 cm).
5-8 ml of a saturated solution of potassium chloride, neutralized with 0.01 N sodium hydroxide, is poured into the tube. alkali solution in the presence of phenolphthalein to a slightly pink color. The end of the tube below the faucet must also be filled with KCl solution so that there are no air bubbles in the tube. A platinum electrode 2 is inserted into the tube 1 using a rubber ring. A platinum electrode 3 is inserted into the second hole of the flask; into the third hole - the end of the burette, which is filled with an alkali solution. One electrode is connected directly to one of the contacts of the galvanometer 4 using a bell wire, the other electrode is connected to the telegraph key 5, and then from it to another contact of the galvanometer.
When determining, 25-50 ml of the test liquid is transferred into a conical flask, if necessary, the volume of liquid in the flask is adjusted to 50-60 ml with freshly boiled distilled water. Quinhydrone (10-20 mg) is added to the flask with liquid at the tip of a knife and the contents are gently mixed. A little quinhydrone is also introduced into a tube with a solution of potassium chloride and stirred with a platinum electrode immersed in it. The flask is stoppered, while the ends of the electrodes must be immersed in the liquid. Then, a burette nozzle with a solution of 0.1 N is inserted into the third hole. alkali. By pressing key 5, the operation of the device is checked by the presence of current in the circuit and the deviation of the galvanometer needle.
The liquid in the flask is then titrated with 0.1 N. alkali solution, adding small amounts of alkali solution and shaking the contents of the flask each time. Then, with short and quick movements, the key is pressed and the movement of the galvanometer needle is noted. Towards the end of the titration, the alkali solution is added one drop at a time. The titration is considered complete if, after the addition of the last drop of alkali, no current is detected in the circuit. By the number of milliliters 0.1 n. alkali solution used for titration, the acidity is calculated according to the generally accepted formula.
After the determination, the flask, electrodes and tube are thoroughly washed off with distilled water. During the period when acidity is not determined, the electrodes should be immersed in distilled water.
Determination of active acidity (pH)
The active acidity of a solution is expressed by the concentration of active hydrogen ions (pH). Acids, alkalis and salts in aqueous solutions dissociate into hydrogen ions H and hydroxyl OH", therefore acidity or is due to the presence of hydrogen or hydroxyl ions in it.
A unit volume of a neutral solution contains an equal number of hydrogen and hydroxyl ions. The concentration of hydrogen ions in pure water is expressed as a negative logarithm and is denoted by the symbol pH (pH). Chemically pure water has a neutral reaction and its pH is lg10-7 = 7.
In an acidic environment, the number of hydrogen ions is greater than the number of hydroxyl ions and the pH value (pH) will be less than 7. In an alkaline environment, hydroxyl ions predominate over hydrogen ions, and the pH value will be greater than 7.
Active acidity is determined mainly by the electrometric method using special instruments - potentiometers. When determining the approximate pH, you can use special indicator papers equipped with a comparison scale. To do this, the test solution is applied to the indicator paper and the pH value is determined from the resulting color, comparing the resulting color with the comparison scale.
Electrometric () method for determining pH. The electrometric method for determining pH is based on measuring the electromotive force (emf) of a galvanic cell assembled from a half-cell of the main electrode immersed in the test solution and a reference half-cell (standard electrode). The essence of the potentiometric method lies in the fact that when a metal electrode is immersed in a solution containing ions of the same metal, due to ion exchange, the electrode is charged and an electric potential arises on it, the value of which depends on the concentration of metal ions in the solution.
The electromotive force can be measured in two ways: using a sensitive voltmeter and the compensation method. The first method is to connect both electrodes through a voltmeter showing the emf value. element. This method is less accurate, since current is continuously consumed during the measurement, and at very low values of the current strength in the concentration element, an error occurs in the results of the emf measurement. Compensation method for measuring emf. most accurate because emf. of the element under study, which causes a current in the circuit, is contrasted with another emf known in magnitude, which also causes a current in the same circuit, but in the opposite direction.
In control practice, to determine pH (pH), special devices are used - potentiometers, the basis of the electrical circuit of which is the compensation method for measuring emf. In these instruments, the division value of the rheochord is calibrated in millivolts or pH units. Millivolts emf converted to pH values according to special tables.
The following potentiometers are most widely used: P-4, LP-5, PPTV-1, LP-58 and LPU-01. The method for determining pH and the schemes of potentiometer devices are usually described in the instructions supplied with the instruments.
When determining pH in solutions that do not contain strong oxidizing agents and reducing agents, you can use a device of a simpler design - the IM-2M ionomer (Fig. 18). The action of the ionomer is based on the measurement of emf with a millivoltmeter. galvanic cell when its electrodes are immersed in the test solution.
The working electrode in the galvanic cell is antimony electrode 1, which is made in the form of a bowl cast from metal antimony. The reference electrode is a saturated silver chloride half-cell 2. The scale of the measuring magnetoelectric device 3 is graduated in millivolts from 0 to 600 and in units of pH from 0 to 12.
The accuracy of the ionomer is low and is within ±0.3pH. However, its use allows you to easily and quickly determine the pH in a wide range (from 1 to 12), and in the temperature range from 10 to 35 ° C. In addition, the ionomer does not require electrical power sources.
What is pH. Hydrogen index. Acid and basic (alkaline) properties of solutions / media.
pH = -log, or more strictly speaking pH = -log(chemists claim that it is in this form that the positive hydrogen ion lives in an aqueous solution). pH indicates the acid/alkaline balance of a solution, not the acidity or alkalinity (basicity) by itself.
pH is measured in powers of 10. The concentration of hydrogen ions in a pH 1.0 solution is 10 times higher than the concentration of hydrogen ions in a pH 2.0 solution. The higher the concentration of hydrogen ions, the lower the pH
- at pH > 7 alkaline solution (basic)
- at pH < 7 sour or acidic solution
In pure neutral water, the concentration of hydrogen ions and hydroxide ions = hydroxide ions = OH are both equal to 10 -7 mol/l.
| pH | Ion concentration mol/l | Mortar type / which ions |
| 0 | 1.0 | Acid solution (sour)
/
|
| 1 | 0.1 | |
| 2 | 0.01 | |
| 3 | 0.001 | |
| 4 | 0.0001 | |
| 5 | 0.00001 | |
| 6 | 0.000001 | |
| 7 | 0.0000001 | Neutral solution |
| 8 | 0.000001 | Basic (alkaline) solution / hydroxide ions oh- |
| 9 | 0.00001 | |
| 10 | 0.0001 | |
| 11 | 0.001 | |
| 12 | 0.01 | |
| 13 | 0.1 | |
| 14 | 1.0 |
In general, chemical theory is more complicated, but pH is an excellent practical indicator of "acidity", "alkalinity" and "neutrality".
Color change of acid-base indicators depending on the pH of the solution. Litmus, phenolphtholein, methyl orange.
* [ x ] - concentration of ions ‘x’
pH table of household substances, materials and products.
| Substance | pH |
|---|---|
| electrolyte in lead batteries | <1.0 |
| Gastric juice | 1,0-2,0 |
| Lemon juice | 2.5±0.5 |
| Lemonade Cola | 2,5 |
| Vinegar | 2,9 |
| Apple juice | 3.5±1.0 |
| Beer | 4,5 |
| Coffee | 5,0 |
| fashion shampoo | 5,5 |
| Tea | 5,5 |
| Acid rain | < 5,6 |
| Skin of a healthy person | ~6,5 |
| Saliva | 6,35-6,85 |
| Milk | 6,6-6,9 |
| Pure water | 7,0 |
| Blood | 7,36-7,44 |
| Sea water | 8,0 |
| Soap (fatty) for hands | 9,0-10,0 |
| Ammonia | 11,5 |
| Bleach (bleach) | 12,5 |
| soda solution | 13,5 |
The pH value of some common foods.
|
Product |
Approximate |
Product |
Approximate |
| apricot nectar | 3.8 | Raspberry | 3.2 — 3.6 |
| apricots | 3.3 — 4.8 | Hominy | 6.8 — 8.0 |
| Avocado | 6.3 — 6.6 | Mango | 5.8 — 6.0 |
| Aloe Vera | 6.1 | Olives | 6.0 — 7.0 |
| oranges | 3.0 — 4.0 | Oil | 6.1 — 6.4 |
| Peanut butter | 6.3 | Molasses (black molasses) | 4.9 — 5.4 |
| Watermelon | 5.2 — 5.6 | Milk | 6.4 — 6.8 |
| artichokes | 5.5 — 6.0 | Carrot | 5.9 — 6.3 |
| Bananas | 4.5 — 5.2 | Abalone | 6.1 — 6.5 |
| Yam (sweet potato) | 5.3 — 5.6 | Wheat flour | 5.5 — 6.5 |
| Sweet potato (sweet) potatoes, boiled. |
5.5 — 6.8 | tomato pulp | 4.3 — 4.5 |
| White bread | 5.0 — 6.2 | Nectarines | 3.9 — 4.2 |
| beans | 5.6 — 6.5 | vegetable juice | 3.9 — 4.3 |
| Broccoli | 5.3 | Perch, sea, fried | 6.6 — 6.8 |
| Wine | 2.8 — 3.8 | Olives | 3.6 — 3.6 |
| Grape | 3.5 — 4.5 | Buttermilk | 4.4 — 4.8 |
| Cherry | 3.2 — 4.5 | Peaches | 3.4 — 4.1 |
| Carbonated drinks | 2.0 — 4.0 | Cod liver | 6.2 |
| Peas | 5.8 — 6.4 | Beer | 4.0 — 5.0 |
| Mustard | 3.5 — 6.0 | Drinking water | 6.5 — 8.0 |
| Grapefruit | 3.0 — 3.7 | Tomatoes | 4.3 — 4.9 |
| Pears | 3.6 — 4.0 | Rhubarb | 3.1 — 3.2 |
| Melon | 6.0 — 6.7 | sardines | 5.7 — 6.6 |
| Blackberry | 3.9 — 4.5 | fresh eggs | 7.6 — 8.0 |
| Raisin | 2.8 — 3.0 | Beet | 4.9 — 6.6 |
| Cactus | 4.7 | Celery | 5.7 — 6.0 |
| squids | 5.8 | Herring | 6.1 |
| capers | 6.0 | Cider | 2.9 — 3.3 |
| Cabbage | 5.2 — 5.4 | Soy milk | 7.0 |
| Cuttlefish | 6.3 | Soy sauce | 4.4 — 5.4 |
| Carp | 6.0 | Sauce Curry | 6.0 |
| Potato | 5.6 — 6.0 | Chili sauce | 2.8 — 3.7 |
| Ketchup | 3.9 | Asparagus | 6.0 — 6.7 |
| Sour cabbage | 3.4 — 3.6 | Cheese | 4.8 — 6.4 |
| Maple syrup | 4.6 — 5.5 | Tomato juice | 4.1 — 4.6 |
| Strawberry wild-strawberry | 3.0 — 3.9 | Tuna | 5.9 -6.1 |
| Strawberry (strawberry) jam | 3.0 — 3.4 | Turnip (turnip) | 5.2 — 5.6 |
| Cranberry juice | 2.3 — 2.5 | Pumpkin | 4.8 — 5.2 |
| Coconut | 5.5 — 7.8 | Vinegar | 2.4 — 3.4 |
| Coconut milk | 6.1 — 7.0 | apple cider vinegar | 3.1 |
| Crab meat | 6.5 — 7.0 | oysters | 5.7 — 6.2 |
| Red pepper | 4.6 — 5.2 | Dates | 6.5 — 8.5 |
| Shrimps | 6.8 — 7.0 | fruit jelly | 2.8 — 3.4 |
| crackers | 6.5 — 8.5 | fruit jam | 3.5 — 4.0 |
| Gooseberry | 2.8 — 3.1 | Fruit cocktail | 3.6 — 4.0 |
| Corn | 5.9 — 7.3 | Sherry | 3.4 |
| Dried apricots (dried apricots) | 3.4 — 3.8 | Horseradish | 5.4 |
| Lime | 1.8 — 2.0 | Tea | 7.2 |
| lime juice | 2.0 — 2.4 | Blueberry | 3.1 — 3.4 |
| Lemons | 2.2 — 2.4 | Spinach | 5.5 — 6.8 |
| Lemon juice | 2.0 — 2.6 | Apples | 3.3 — 3.9 |
| Salmon | 6.1 — 6.3 | ||
| Leek | 5.5 — 6.2 |
Table. pH values of bases, alkalis (solutions)
The pH values for some common bases and alkalis are shown in the table below.
|
Bases, alkalis |
Solution normality |
|
| Ammonia / Ammonia | n. | 11.5 |
| Ammonia / Ammonia | 0.1 n. | 11.1 |
| Ammonia / Ammonia | 0.01 n. | 10.6 |
| Sodium acetate | 0.1 n. | 8.9 |
| Barbital - sodium / Barbital sodium | 0.1 n. | 9.4 |
| Sodium benzoate / Sodium benzoate | 0.1 n. | 8.0 |
| Potassium bicarbonate / Potassium bicarbonate | 0.1 n. | 8.2 |
| Sodium bicarbonate / Sodium bicarbonate | 0.1 n. | 8.4 |
| Ferrous hydroxide | saturated | 9.5 |
| n. | 14.0 | |
| Potassium hydroxide / Potassium hydroxide | 0.1 n. | 13.0 |
| Potassium hydroxide / Potassium hydroxide | 0.01 n. | 12.0 |
| Calcium hydroxide / Calcium hydroxide | saturated | 12.4 |
| n. | 14.0 | |
| Sodium hydroxide / Sodium hydroxide | 0.1 n. | 13.0 |
| Sodium hydroxide / Sodium hydroxide | 0.01 n. | 12.0 |
| Calcium carbonate / Calcium carbonate | saturated | 9.4 |
| Sodium metasilicate / Sodium metasilicate | 0.1 n. | 12.6 |
| Magnesium oxide / Magnesia | saturated | 10.5 |
| Sodium pyroborate (Bura)/ Borax | 0.01 n. | 9.2 |
| Sodium sesvicarbonate / Sodium sesquicarbonate | 0.1 n. | 10.1 |
| Trisodium phosphate / Trisodium phosphate | 0.1 n. | 12.0 |
| Potassium carbonate / Potassium carbonate | 0.1 n. | 11.5 |
| Sodium carbonate / Sodium carbonate | 0.1 n. | 11.6 |
| Potassium acetate / Potassium acetate | 0.1 n. | 9.7 |
| Potassium cyanide / Potassium cyanide | 0.1 n. | 11.0 |
Table of PH values of acids. (Solutions).
The table shows sulfuric, acetic and other common acids.
pH is a measure of the activity of hydrogen ions in solutions, and thus their acidity or alkalinity. Thus, the table below shows the acidity of some common acids.
|
Acid |
Solution normality |
|
| Nitrogen / Nitric | 0.1n. | 1.0 |
| Aluminum alum / Alum | 0.1 n. | 3.2 |
| Benzoic / Benzoic | 0.1 n. | 3.0 |
| Boric / Boric | 0.1 n. | 5.2 |
| Wine / Tartaric | 0.1 n. | 2.2 |
| Gastric Juice / Stomach Acid | 1 | |
| Lemon / Citric | 0.1n. | 2.2 |
| Lemon Juice | 2 | |
| Dairy / Lactic | 0.1 n. | 2.4 |
| Formic / Formic | 0.1 n. | 2.3 |
| Arsenic / Arsenious | saturated | 5.0 |
| Oksyantarnaya (apple) / Malic | 0.1 n. | 2.2 |
| Orthophosphoric / Orthophosphoric | 0.1 n. | 1.5 |
| Salicylic / Salicylic | saturated | 2.4 |
| Sulfuric / Sulfuric | n. | 0.3 |
| Sulfuric / Sulfuric | 0.1 n. | 1.2 |
| Sulfuric / Sulfuric | 0.01 n. | 2.1 |
| Sulphurous / Sulfurous | 0.1 n. | 1.5 |
| Hydrogen sulfide | 0.1 n. | 4.1 |
| Trichloroacetic / Trichloracetic | 0.1 n. | 1.2 |
| Coal (Carbon) / Carbonic | saturated | 3.8 |
| Vinegar (3-15%) / Vinegar | 3 | |
| Vinegar / Acetic | 2.4 | |
| Vinegar / Acetic | 0.1 n. | 2.9 |
| Vinegar / Acetic | 0.01 n. | 3.4 |
| n. | 0.1 | |
| Hydrochloric / Hydrochloric | 0.1 n. | 1.1 |
| Hydrochloric / Hydrochloric | 0.01 n. | 2.0 |
| Hydrocyanic (hydrocyanic) / Hydrocyanic | 0.1 n. | 5.1 |
| Oxalic / Oxalic | 0.1 n. | 1.3 |
| Amber / Succinic | 0.1n. | 2.7 |
Hydrogen indicator (pH factor) is a measure of the activity of hydrogen ions in a solution, quantifying its acidity. When the pH is not at the optimal level, the plants begin to lose the ability to absorb some of the elements needed for healthy growth. For all plants there is a specific pH level that allows you to achieve maximum results when growing. Most plants prefer a slightly acidic growing medium (between 5.5-6.5).
Hydrogen indicator in formulas
In very dilute solutions, the pH is equivalent to the concentration of hydrogen ions. Equal in modulus and opposite in sign to the decimal logarithm of the activity of hydrogen ions, expressed in moles per liter:
pH = -lg
Under standard conditions, the pH value lies in the range from 0 to 14. In pure water, at neutral pH, the concentration of H + is equal to the concentration of OH - and is 1·10 -7 mol per liter. The maximum possible pH value is defined as the sum of pH and pOH and is equal to 14.
Contrary to popular belief, pH can vary not only in the range from 0 to 14, but can also go beyond these limits. For example, at a concentration of hydrogen ions = 10 −15 mol/l, pH = 15, at a concentration of hydroxide ions of 10 mol/l pOH = −1.
It's important to understand! The pH scale is logarithmic, which means that each unit of change equals a tenfold change in the concentration of hydrogen ions. In other words, a pH 6 solution is ten times more acidic than a pH 7 solution, and a pH 5 solution will be ten times more acidic than a pH 6 solution and a hundred times more acidic than a pH 7 solution. This is means that when you are adjusting the pH of your nutrient solution and you need to change the pH by two points (e.g. from 7.5 to 5.5) you must use ten times more pH adjuster than if you only changed the pH by one point (from 7.5 to 6.5). ).
Methods for determining the pH value
Several methods are widely used to determine the pH value of solutions. The pH value can be approximated using indicators, accurately measured with a pH meter, or determined analytically by performing an acid-base titration.
Acid-base indicators
For a rough estimate of the concentration of hydrogen ions, acid-base indicators are widely used - organic dye substances, the color of which depends on the pH of the medium. The most famous indicators include litmus, phenolphthalein, methyl orange (methyl orange) and others. Indicators can exist in two differently colored forms, either acidic or basic. The color change of each indicator occurs in its acidity range, usually 1-2 units.
Universal indicator
To extend the working range of pH measurement, the so-called universal indicator is used, which is a mixture of several indicators. The universal indicator consistently changes color from red through yellow, green, blue to purple when moving from an acidic region to a basic one.
Solutions of such mixtures - "universal indicators" are usually impregnated with strips of "indicator paper", with which you can quickly (with an accuracy of pH units, or even tenths of pH) determine the acidity of the aqueous solutions under study. For a more accurate determination, the color of the indicator paper obtained by applying a drop of solution is immediately compared with the reference color scale, the form of which is shown in the images.
Determination of pH by the indicator method is difficult for cloudy or colored solutions.
Given the fact that the optimal pH values for nutrient solutions in hydroponics have a very narrow range (usually from 5.5 to 6.5), other combinations of indicators are also used. So, for example, ours has a working range and a scale from 4.0 to 8.0, which makes such a test more accurate than universal indicator paper.
pH meter
The use of a special device - a pH meter - allows you to measure pH in a wider range and more accurately (up to 0.01 pH units) than with universal indicators. The method is convenient and highly accurate, especially after calibration of the indicator electrode in the selected pH range. Allows you to measure the pH of opaque and colored solutions and is therefore widely used.
Analytical volumetric method
Analytical volumetric method - acid-base titration - also gives accurate results for determining the acidity of solutions. A solution of known concentration (titrant) is added dropwise to the test solution. When they are mixed, a chemical reaction takes place. The equivalence point - the moment when the titrant is exactly enough to completely complete the reaction - is fixed using an indicator. Further, knowing the concentration and volume of the added titrant solution, the acidity of the solution is calculated.
Effect of Temperature on pH Values
The pH value can change over a wide range as the temperature changes. Thus, a 0.001 molar solution of NaOH at 20°C has pH=11.73, and at 30°C pH=10.83. The effect of temperature on pH values is explained by the different dissociation of hydrogen ions (H+) and is not an experimental error. The temperature effect cannot be compensated by the electronics of the pH meter.
Adjusting the pH of the Nutrient Solution
Acidification of the nutrient solution
The nutrient solution usually needs to be acidified. The absorption of ions by plants causes a gradual alkalinization of the solution. Any solution having a pH of 7 or higher will most often need to be adjusted to the optimum pH. Various acids can be used to acidify the nutrient solution. Most often, sulfuric or phosphoric acid is used. A better solution for hydroponic solutions are buffer additives such as and. These products not only bring the pH values to the optimum, but also stabilize the values for a long period.
When adjusting the pH with both acids and alkalis, rubber gloves should be worn to avoid burns to the skin. An experienced chemist skillfully handles concentrated sulfuric acid, he adds acid to water drop by drop. But as a beginner hydroponist, it's probably best to ask an experienced chemist to prepare a 25% sulfuric acid solution. While the acid is being added, the solution is stirred and its pH is determined. Having learned the approximate amount of sulfuric acid, in the future it can be added from a graduated cylinder.
Sulfuric acid must be added in small portions so as not to acidify the solution too much, which then has to be alkalized again. For an inexperienced worker, acidification and alkalization can go on indefinitely. In addition to wasting time and reagents, such regulation unbalances the nutrient solution due to the accumulation of ions that the plants do not need.
Alkalinization of the nutrient solution
Too acidic solutions are alkalized with sodium hydroxide (sodium hydroxide). As its name suggests, it is caustic so rubber gloves should be worn. It is recommended to purchase caustic sodium in the form of pills. In household chemical stores, caustic sodium can be purchased as a pipe cleaner, such as Mole. Dissolve one pill in 0.5 l of water and gradually pour the alkaline solution into the nutrient solution with constant stirring, checking its pH frequently. No mathematical calculations can calculate how much acid or alkali needs to be added in this or that case.
If you want to grow several crops in one pallet, you need to select them so that not only their optimal pH, but also the needs for other growth factors coincide. For example, yellow daffodils and chrysanthemums need a pH of 6.8, but a different humidity regime, so they cannot be grown on the same pallet. If you give daffodils as much moisture as chrysanthemums, the daffodil bulbs will rot. In experiments, rhubarb reached its maximum development at pH 6.5, but could grow even at pH 3.5. Oats, which prefer a pH around 6, produce good yields even at pH 4 if the amount of nitrogen in the nutrient solution is greatly increased. Potatoes grow over a fairly wide pH range, but grow best at a pH of 5.5. Below this pH, high yields of tubers are also obtained, but they acquire a sour taste. To obtain maximum yields of high quality, the pH of nutrient solutions must be precisely controlled.
pH (from the English power Hydrogen - "Activity / strength of hydrogen") is an indicator that is used to determine the ratio of acid (base) in any solution. The term is inextricably linked with the concept of acid-base balance (ABR).
Although in scientific terminology the concept of pH-environment is applied literally to any solution, in modern popular scientific this term is used mainly to denote the ratio of acid and alkali in the human body.
What pH indicator can speak of a normal normal environment? It is recognized that at a pH of 7.0 the medium can be called "neutral" - the activity of positively charged ions and negatively charged ions in such an environment is the same. However, an acid-base balance is almost never formed in the human body - three slices of lemon are enough to outweigh the indicator in the direction of increased acidity.
The human body constantly fights for the balance of the acid-base environment, trying to restore this balance through internal mechanisms if it is disturbed, since the absence of AChR can lead to an undermining of the immune system.
The role of acid-base balance in the body
There are three states of the acid-base environment in the body: a balanced state of the environment, increased acidity (acidosis) and an increased alkali content in the body (alkalosis).
Increased acidity leads to poor absorption of minerals by the body: magnesium, potassium - they are all simply excreted from the body without having time to digest. Increased acidity adversely affects the functioning of many organs, especially the gastrointestinal tract, kidneys and the cardiovascular system. The main complications that can be caused by acidosis are:
Fragility of bones (as a result of calcium indigestion);
- weight gain;
- kidney dysfunction;
- allergic reactions;
- decreased immunity;
- general weakness.
Most often, a person feels the increased acidity of the environment with the intestines and stomach - then a slight burning sensation or even heartburn that occurs after a large amount of alcohol drunk or eaten lemon speaks of increased acidity.
The opposite of hyperacidity is called alkalosis - an increased alkali content in the body. In fact, causing a truly elevated level of alkali in the body is not entirely simple - most often this condition occurs after long-term use of drugs containing alkali. In addition, this condition does not contribute to the development of such serious problems as acidosis. Possible complications as a result of alkalosis:
skin problems;
- smell from the mouth;
- problems with the intestines;
- possible occurrence of allergic reactions to some products.
The key to the balance of the acid-base environment is harmonious nutrition and the rejection of alcohol (those who like to "drink on Fridays" have an acid-base balance approximately 1.5% -2.0% higher than those who do not drink). Enzymes, vitamin complexes and mineral complexes, especially calcium in large dosages, are most often used to restore the ASC.
Can you imagine that the development of many diseases depends on one cause? Many nutritionists and phytotherapists now refer to this hidden danger in two words: acid and alkali.
High acidity destroys the most important systems in the body, and it becomes defenseless against diseases. A balanced pH environment ensures the normal flow of metabolic processes in the body, helping it fight diseases. A healthy body has a supply of alkaline substances that it uses when needed.
What is pH?
The ratio of acid and base in any solution is called acid-base balance (ABA), although physiologists believe that it is more correct to call this ratio the acid-base state. KShchR is characterized by a hydrogen indicator pH (from lat. p ondus H hydrogenii - "weight of hydrogen", pronounced "pash"), which indicates the number of hydrogen atoms in a given solution.
The pH value depends on the ratio between positively charged ions(forming an acidic environment) and negatively charged ions(forming an alkaline environment).
PH is a measure of the relative concentration of hydrogen (H+) and hydroxide (OH-) ions in a liquid system and is expressed on a scale from 0 (full saturation with hydrogen ions H+) to 14 (full saturation with hydroxyl ions OH-), distilled water is considered neutral with pH 7.0.
0 is the strongest acid, 14 is the strongest alkali, 7 is a neutral substance.
Why do we need to know about pH?
The human body is 80% water, so water is one of its most important constituents. Therefore, the pH of this water will determine how healthy we will be.
A pH of 7.0 is said to be neutral. The lower the pH level, the more acidic the environment (from 6.9 to 0). An alkaline environment has a high pH (7.1 to 14.0).
The human body constantly strives to balance this ratio, maintaining a strictly defined pH level. When the balance is disturbed, many serious diseases can occur.
If in any of the liquid media of the body there is an increase in the concentration of (H +) ions, then there is a shift in pH to the acid side, that is, acidification of the medium occurs. This is also called acid shift.
Conversely, an increase in the concentration of (OH-) ions causes a shift in the pH value to the alkaline side, or an alkaline shift.
Our body has a slightly alkaline environment. The acid-base balance in our body is constantly maintained at one stable level and in a very narrow range: from 7.26 to 7.45. And even a slight change in blood pH that goes beyond these limits can lead to disease.
Increased acidity in the body.
Due to malnutrition and eating acidic foods, as well as lack of water, acidification of the body. People consume a lot of fats, meat, dairy products, cereals, sugar, flour and confectionery products, all kinds of semi-finished products and other processed, refined products that contain practically no fiber, minerals and vitamins, not to mention enzymes and unsaturated fatty acids.
In order to resist this - to reduce the concentration of acid and remove it from the vital organs - the body retains water, which negatively affects the metabolism: the body wears out faster, the skin becomes dry, wrinkled.
In addition, when the body is acidified, oxygen transfer to organs and tissues worsens, the body does not absorb minerals well, and some minerals, such as Ca, Na, K, Mg, are excreted from the body.
The body has to spend a huge amount of resources and energy to neutralize excess acids, thereby causing a certain imbalance in biochemical reactions.
Since the alkaline reserves coming from outside are clearly not enough, then the body is forced to use its internal resources - calcium, magnesium, iron, potassium. As a result, hemoglobin decreases, osteoporosis develops.
When the blood hemoglobin iron is used to neutralize the acid, the person feels tired.
If calcium is consumed for these needs, insomnia and irritability appear.
Due to the decrease in the alkaline reserve of the nervous tissue, mental activity is disturbed.
Vital organs suffer from a lack of minerals, the risk of cardiovascular diseases increases, immunity decreases, bone fragility appears, and much more.
If there is a large amount of acid in the body and the mechanisms of its excretion are disturbed (with urine and feces, with breathing, with sweat, etc.), the body undergoes severe intoxication.
What causes an increased level of acidity in the body?
On a global scale acidification of the body leads to more than 200 (!) Diseases, for example: cataracts, farsightedness, arthrosis, chondrosis, bile and urolithiasis, and even oncology.
Knowing this, one ceases to wonder why humanity has so many diseases, why people grow old and die early.
Think about it: more than 90% of the food we eat is "sour" foods, and everything we drink (except pure water, freshly squeezed juices and herbal tea without sugar) has a pH of 4.5 to 2.5 - that is acidifies our body even more.
The condition of hyperacidity is called - Acidosis. Acidosis not detected in time can harm the body imperceptibly, but constantly for several months and even years. Alcohol abuse often leads to acidosis. Acidosis can occur as a complication of diabetes.
Acidosis can cause the following problems:
- Diseases of the cardiovascular system, including persistent vasospasm and a decrease in the concentration of oxygen in the blood, heart failure, weakening of the heart muscle.
- Weight gain and diabetes.
- Diseases of the kidneys and bladder, the formation of stones.
- Digestive problems, weakening of the smooth muscles of the intestines, and so on.
- Decreased immunity.
- General weakness.
- An increase in the harmful effects of free radicals, which can contribute to oncogenesis.
- Fragility of bones up to a fracture of the femoral neck, as well as other disorders of the musculoskeletal system, such as the formation of osteophytes (spurs).
- The appearance of joint pain and pain in the muscles associated with the accumulation of lactic acid.
- The gradual weakening of the work of the eye muscles, the development of farsightedness, which is very common among the elderly.
- Decreased stamina and ability to recover from exercise.
For 7 years, a study was conducted at the University of California (San Francisco), where 9 thousand women were examined. The results showed that with a constant high level of acidity, the bones become brittle.
The experts who conducted this experiment are sure that most of the problems of middle-aged women are associated with excessive consumption of meat and dairy products and a lack of eating vegetables, fruits and herbs. Therefore, the body has no choice but to take calcium from its own bones, and with its help regulate the pH level.
How does the body manage acid levels?
- It releases acids - through the gastrointestinal tract, kidneys, lungs, skin;
- Neutralizes acids - with the help of minerals: calcium, magnesium, potassium, sodium;
- Accumulates acids - in the tissues, especially in the muscles.
What to do if the pH balance is normal?
The answer is simple - to help maintain this balance in a healthy zone.
How to do it?
Constantly monitor what we eat, what we drink, how clean we are from the inside and how we protect our body from harmful influences.
Water.
It is necessary to drink enough, and specifically - 30 ml per kilogram of weight per day (in the hot summer months, you can 2-3 times more).
Food.
If the acid-base balance is already disturbed, then you should think about your diet, and reduce the consumption of acidic foods (meat and dairy products, bread, sweets, carbonated drinks, any artificially created foods) and increase the consumption of alkalizing foods. If it is not possible to change the composition of the diet, then it is worth considering the use of "smart food" (smart food) - nutraceuticals that compensate for the lack of vitamins, minerals, amino acids, polyunsaturated fatty acids and plant enzymes coming from food.
Also, one should not forget about the regular cleansing of the body, physical activity and the psychology of a positive attitude towards life. All this is part of a simple and accessible explanation of the causes of most diseases and showing the possibilities of restoring and maintaining health.
Getting younger and becoming healthier over the years is real!
Why is it important to maintain the correct pH balance?
A slightly acidic environment is needed to start various chemical processes (for example, digestion - in the stomach the environment is slightly shifted towards acidity), but the blood should not be slightly acidic - if the pH balance in the blood is changed, then the processes will not go as planned.
After all, the blood contains all our building material (transferred from the liver), proteins, antibodies, fat genes, white blood cells, nutrients and a whole bunch of other things. They are tuned to work in just such a range (7.35-7.45) and the slightest shift disrupts the operation of the entire system (blood is everywhere, we have 85,000 km of veins and arteries, but only 5 liters of blood).
All regulatory mechanisms of the body (including respiration, metabolism, hormone production) are aimed at balancing the pH level, by removing caustic acid residues from body tissues without damaging living cells. If the pH becomes too low (acidic) or too high (alkaline), then the cells of the body poison themselves with their toxic emissions and die.
The importance of the balance of this entire system is also emphasized by the following fact: to maintain a balance between acid and alkali, the body takes calcium from the bones(our calcium bank) and magnesium(they are inextricably linked with calcium), to alkalize acid.
What should chronicles do?
Even the "most correct" nutrition program, or a program for the treatment of any disease, will not work effectively if your body's pH balance is disturbed.
A constant load on the compensatory systems of the body for many years and decades greatly harms the body, wears it out. Gradually and steadily there is a bias in the work of all systems and metabolic processes.
This cannot continue indefinitely and without consequences. Chronic diseases arising against this background are simply impossible to cure with the help of medicines.
Here, the only and best “cure” can be only one: completely rebuild the diet, eliminate the acid load, eat mainly raw plant foods for many years - until all functions, all processes in the body return to normal parameters and the imbalance disappears.
If a person understands the importance of reviewing nutrition, but for some reason he cannot strictly follow such a diet, then in this case alkalizing food supplements (smart food) can be used.
To live a full, healthy life, the only way out is to alkalize the body.
How we do this depends entirely on our choice. Some will be able to fully follow the advice to change their diet and become a vegan or raw foodist. And someone (like me, for example) will face the fact that it is difficult for him.
And then the question arises:
WHAT SHOULD I, THE ORDINARY PERSON, DO?
I have chosen for myself the system for restoring the acid-base balance from the Coral Club (Coral Club) and have been successfully using it in my life for quite a long time. During this time, my body has changed both externally and internally.
Read more about the simplest and safest alkalization program here.
If you are interested in this system and want to learn more about it or start using it as soon as possible - to get detailed advice.
Source of part of the text - ecology.md
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