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ISPITIVANJE ZEMLJIŠTA IZ ŠKOLSKOG

DVORIŠTA U ŠKOLSKOJ LABORATORIJI

Aleksandra Mikid, Ana Golubovid , učenice VII4 Osnovna škola Vuk Karadžid, Beograd

Mentor: Ljiljana Grkovid, Osnovna škola Vuk Karadžid, Beograd

Rezime

Zemljište predstavlja površinski sloj litosfere. Odlikuje se hemijskim, agrohemijskim, fizičkim i biološkim osobinama.
Za pravilno očuvanje neophodno je njihovo poznavanje, zato što se zemljište vrlo sporo obnavlja. U ovom radu
istražile smo sadržaj karbonata, hlorida, sulfata, kiselost i vlažnist iz školskog dvorišta u školskoj laboratoriji.

- Karbonate smo određivale pomodu 10% rastvora hlorovodonične kiseline. Na osnovu pene koja se pojavila
(zbog izdvajanja ugljen-dioksida), utvrdile smo sadržaj karbonata.

- Hloride smo ispitivale pomodu destilovane vode i srebro-nitrata. Kada se pojavio beo, zgrušan talog, utvrdile
smo postojanje hlorida.
- Sulfate smo ispitivale pomodu barijum-hlorida. Pojavom belog taloga utvrdile smo da zemljište sadrži sulfate.

- Ispitani uzorak zemljišta pokazao je da je njegova pH vrednost 6,3, što dokazuje da je zemljište slabo kiselo.

- Vlažnost je ispitivana merenjem mase uzorka zemljišta pre i posle tretiranja u sušionici, a rezultati su izraženi u
procentima. To je pokazalo da u ispitivanom uzorku zemljišta ima 24,7% vlage.

Ključne reči: Agrohemijske osobine zemljišta, Karbonati, Hloridi, Sulfati, Kiselost i Vlažnost.

Abstract:

Soil is a surface layer of litosphere. It is shaped by chemical, agrochemical, phisical and biological features. For the
well preservation of soil it is neccessary to know them very well, because soil is regenerating very slow.
This investigational work studies the containing of carbonates, chlorides, sulphates, acidity and humidity of school
yard in the school laboratory.

- We determined carbonates with 10% solvate of HCl. On the basis of frothing which appeared (because of
extracting of CO2), we declared containing of carbonates.

- We researched chlorides by using destillated water and AgNO3. When the white coagulated residue appeared,
we declared containing of chlorides.

- We researched sulphates by using BaCl2. After the white residue appeared we declared that the soil contains
sulphates.

- Researched sample of soil showed us that its pH value is 6,3 , which was a proof that the soil has low acidity.
- Humidity is researched by testing mass of sample( of soil) before and after treatment in kiln, and the results are
prounced in percents. It showed us that the researched sample of soil is 24,7% humid.

Key words: Agrochemical features of soil, Carbonates, Chlorides, Sulphates, Acidity and Humidity.