Tip 1: How to determine the acidity of the water

The water always contains a certain amount of hydrogen ions H ^ +, and hydroxyl ions OH ^ -.When hydrogen ions more water becomes acidic character if more hydroxyl ions, alkaline.To assess the degree of acidity of the aqueous solution the pH value exists.It is numerically equal to the negative decimal logarithm of the hydrogen ion activity, a unit of its dimensions - mol / liter.That is pH = -lg [H ^ +].The pH ranges from 0 to 14. If it is less than 7, the solution was acidic.Accordingly, if more than 7 - alkaline.
you need
  • - indicator of paper;
  • - laboratory pipette or plastic tube;
  • - transparent container;
  • - indicator substance;
  • - pH-meter.
Guide
1
there are quick and easy, it's not a very accurate method for determining the acidity of water - with the help of indicator papers (strips).They can be bought in stores of chemical reagents or get it in the laboratory.On the packaging there is always a reference comparison scale, where each value of pH corresponds to a definite colorati
on - from cherry burgundy (strongly acidic medium, pH = 0) and dark blue (strongly alkaline medium, pH = 14).
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To determine the acidity of the water , it is necessary with a laboratory pipette or a plastic tube put one drop on the test strip.In an extreme case, just dip the tip of the strip into the water.Then quickly compare the resulting color with the reference scale.The strip changes color only when water pH close to neutral indicator (7,0).
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If these papers (strips) is not possible to use solutions of indicators.From the school chemistry course you are probably familiar names: litmus, methyl orange, phenolphthalein.
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Pour water into the transparent container, add a bit of each indicator substance.After that vote discoloration.Litmus in acidic medium receives red and alkaline - blue.Phenolphthalein alkaline environment is bright crimson.Methyl Orange in a strongly acidic medium receives red color, and in slightly acidic medium turns yellow.Of course this method is suitable only for determining the nature of an aqueous solution.On any precise pH there can be no question.
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most accurately determine the pH (ie acidity level) with the help of special instruments - pH meters.They are available in a very wide range.There are simple, compact pH meters that can be used virtually anywhere, there is a very complex and expensive, which is used only in laboratories.The principle of operation of such devices is based on measuring the electrical potential of the reference electrode immersed in the test solution.

Tip 2: How to measure the acidity of the soil

Soil acidity - is one of the main criteria of its quality.It depends on the prevalence in the soil or other chemical elements and divided into acidic, neutral or alkaline depending on the pH.
How to measure the acidity of the soil
you need
  • - litmus paper;
  • - chalk;
  • - rubber gloves.
Guide
1
Before measuring acidity remember that the level of soil pH distinguish strongly acidic with a pH range of 3-4, acidic - pH 4-5, slightly acid soil - 5-6 pH neutral- 6-7 pH, alkaline soils have a pH in the range 7-8, and strongly alkaline - pH 8-9.This value varies from 0 to 14. The change in pH by 1 pH unit means a change in one or another direction 10 times.
2
To determine the pH to within the unit use litmus paper.In the area of ​​soil dig a hole depth of about 30 cm, take a sample from its vertical walls from top to bottom.
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soil mix well and add purified or distilled water.The resulting slurry dip litmus paper, which is impregnated with water and washed it out of the soil chemicals.Depending on the level of acidity of the soil study litmus will change its color.When comparing the resulting color with the accompanying standard scale litmus color change can determine the acidity of the soil.
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If the color of litmus changed to become red - soil is acidic, pink color indicates the average degree of acidity of the soil, and yellow - weak acidity.If the color of litmus blue and green - the soil pH neutral or close to neutral.
5
determine the acidity of the soil by the method Klytchnikova as follows.Take a sample of dry land investigated in an amount of 30 g, and fill in a container of boiling water in a volume of 50 ml.Then take the 7 g of chalk, wrap in paper and immerse in a container with soil suspension.
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neck of the container, close the rubber signet or napalechnikom, wrap it in a cloth to prevent heat and carefully stir.If the test soil is acidic (pH less than 4.5) - in cooperation with chalk will release carbon dioxide, the pressure around the container rises and inflates a rubber fingertip completely.If fingertip pouted half - pH mildly - up to 6, and if the gum remained flat - investigated the soil has a neutral pH with a value of approximately 7.
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also define acidity possible with the help of special devices pH meters that need to bein the study placed in the studied soil - and it will show the value of its pH to within a few tenths.

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