The solubility merchandise invariable was determined at different temperature through acid-base titration against NaOH. This survey concluded that solubility merchandise invariable of K H tartrate is dependent merely on temperature. Introduction The purpose of this experiment is to look into the solubility merchandise invariable of K H tartrate in H2O and it dependance on temperature.
This study aimed to analyze the ecotoxicity of nitrogen- phosphorus- and potassium-based compounds to organisms of two different trophic levels in order to compare the toxic effect between high-purity substances and these substances as components of fertilizers.
Ten individuals of the benthic snail Biomphalaria glabrata and the fish Danio rerio were exposed to each concentration of tested compounds.
As a result, the toxicity levels of potassium chloride, potassium nitrate, and urea were obtained for B. Regarding superphosphate, no significant toxicity was found. This study concluded that among the tested substances, KNO3 and KCl were the most toxic substances and urea the least toxic.
It was not possible to establish the most sensitive species since, for KCl, the fish were more susceptible to the fertilizer and the snail to the reagent, while for KNO3 the opposite was observed. Introduction Within the agricultural production chain, nitrogen Npotassium Kand phosphorus P are of great importance for the practice of agriculture.
In the production process it is difficult for the farmer to obtain a high yield without using at least phosphate- nitrogen- and potassium-based fertilizers.
According to the International Fertilizer Industry Association [ 1 ], on averagemillion tons of nitrogen, 40, million tons of phosphate, and 27, million tons of potassium are used each season worldwide. Nitrogen, when in aqueous medium, is converted into ammonia, nitrite, and nitrate in a three-step process [ 2 ].
It is known that of these three ions, ammonia is the most toxic to aquatic organisms [ 3 ], but these compounds often exist at low concentrations in aquatic ecosystems because they are the main source of nitrogen for primary producers [ 4 ].
The ecological imbalances and the risks for human consumption are now considered when nitrate and nitrite concentrations become high, due to nutrients deposited in the water body through activities such as agriculture and livestock [ 3 ].
Phosphorus can occur in natural and waste waters almost entirely in the form of phosphates. These are classified into orthophosphates, organic phosphates, and condensed phosphates pyrometaphosphate and other polyphosphates. The third of these is not very relevant to water quality control studies, because condensed phosphates hydrolyze, quickly becoming orthophosphates in natural waters [ 2 ].
The discharge of phosphates from raw or treated sewage, agricultural drainage, or certain industrial waste can stimulate the growth of micro and macro photosynthetic organisms in large amounts, triggering the eutrophication process [ 2 ].
Potassium K is one of the elements most needed by crops; however, its fixation in the soil is more difficult since its salts have low cation exchange capacity [ 56 ].
This compound is usually extracted from marine sedimentary deposit sources in the form of KCl or potassium sulfate K2SO4 [ 7 ].
K is also involved in the salinization of the water process, and in some places this salinization can change the composition of local fauna [ 8 ]. Due to this effect on salinity, potassium acts indirectly in the toxicity even when present in small concentrations [ 9 ]. In the presence of water, many compounds are biochemically interconverted into ions [ 2 ].
Other substances present in these compounds, such as impurities, ions, metals, organic contaminants, and even microorganisms, will interact with elements in the environment [ 10 ]. When they are transported to a water source, such as lakes, streams, and ponds, the compounds generally undergo alterations in quantity, be it dilution, reconcentration, or transfer.
They also undergo alterations in their quality, being changed by degradation processes or multiple reactions that may act during the transport process, forming compounds with distinct properties; in turn, these may even increase or decrease the toxicity of the compound [ 11 ].
Works that deal with the action of these ions alone are important in the literature, since the interaction of the elements in the environment can induce toxicity in others [ 12 ], as occurs with potassium. It has been observed that when in ionic form, potassium compounds raise the toxicity of other chemicals, such as nitrate [ 910 ], and that the different forms of soluble nitrogen can define their impact on the environment [ 131415 ].
Another study showed that, when in an aqueous solution, cadmium has its toxic effect maximized, depending upon the calcium concentrations in the water [ 16 ]. It has also been observed that diluted calcium can reduce the toxicity of phosphate by promoting its precipitation [ 1718 ].
The choice was made to use a chemical reagent and a commercial fertilizer in this study after the authors reviewed articles on the ecotoxicology of compounds used as fertilizers. Those that reported the origin of the element used showed a preference for chemical reagents instead of commercial fertilizers.
This fact has some implications within the results analysis, because most of the commercialized fertilizers do not possess the purity that chemical reagents present.
This range makes it difficult to understand if the toxicity is related to the test substance or to impurities contained in the commercial product formulation.
The study aimed to analyze the toxicity of nitrogen- phosphorus- and potassium-based compounds in different forms in two organisms from different trophic levels in order to compare the toxic effect between high-purity substances and those used as a component of fertilizer, seeking to identify the element present in the compound responsible for toxicity and the increase or reduction in toxicity.
Materials and Methods The species used in this study were the benthic snail Biomphalaria glabrata and the zebrafish Danio rerioinvolving species from two different trophic levels, the first one being a mollusk and the second a fish.
Both are freshwater organisms, aiming to cover organisms with distinct biological characteristics and habits, since the snail is a benthic organism and the fish is pelagic. Many studies have already been carried out with planktonic organisms, but few with benthic organisms and, thus, the need to evaluate a model of this trophic level.
Fish were included because they are key organisms in aquatic environments, and to be able to obtain a comparative susceptibility with the snails. From this choice, dilutions were made of the respective commercial fertilizers CFand their equivalent chemical reagents CR were used as active ingredients, namely, potassium chloride, J.
All of these concentrations were defined based on preliminary tests. The concentrations used in the definitive tests were variable for each CR, being obtained from preliminary tests with about three well-spaced dilutions. The acute test method for snails was proposed by Oliveira-Filho et al.
In tests with snails the static exposure system was used, and the solutions were prepared only at the beginning of the test, without renewal until the end of exposure.
For urea, in particular, and for all tests with fish, the semi-static methodology was used, where solutions were renewed daily to avoid losses by volatilization and degradation, as recommended by guideline EPA R [ 23 ].
During the test, pH and dissolved oxygen were checked daily with the intention of identifying possible abrupt changes in those parameters during the exposure period.homologous series: family of organic compounds saturated single bonds unsaturated double or triple bonds aromatic benzene ring meth 1 eth 2 pop 3 but 4 pent 5 hex 6 hept 7 oct 8 non 9 Read more.
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AS and A Level resources with teacher and student feedback. Popular AS and A Level Subjects; Biology (2,) Business Studies (3,) English Literature (8,) Geography (2,) Healthcare (1,) History (6,) Economics. As a result, the toxicity levels of potassium chloride, potassium nitrate, and urea were obtained for B.
glabrata and D. rerio, with the fish being more susceptible to potassium chloride in the fertilizer and the snail to potassium nitrate and urea, in both commercial and reagent forms. The Study Of Solubility Equilibrium Biology Essay Published: November 2, The first part of this experiment aims to determine the solubility product constant of potassium hydrogen tartrate in water, and thereby determine how the enthalpy and entropy change of the dissolution reaction, according to the equilibrium KHC4H4O6 (s) ïƒ› K+ (aq.
Overall procedures involved mixing 9 different solvents with isooctane and observing solubility with the naked eye. It was concluded that 5 of the combinations proved soluble, 2 completely insoluble, and 2 were insoluble at room temperature but soluble if heated. Potassium nitrate is a salt which can be prepared by reacting an acid with an alkali, using the titration method.
i. name an acid and an alkali which react to make potassium nitrate ii. explain why the titration method is suitable for the preparation of potassium nitrate.