Using Experiments To Identify An Unknown Compound Environmental Sciences Essay

Abstract. The intent of this experiment was to place the unknown compound. The trials that were done to find the individuality of the compound include qualitative solubility trials, quantitative solubility trials, mensurating solution conduction, anion and cation trial, fire trial, and formation of precipitate. It was found that the compound had no odor, was soluble in H2O, and non soluble in methylbenzene and propanone. The ions dissociated in the H2O, making conduction. When the ammonium hydroxide trial was performed no ammonium hydroxide odor was produced. The flame trial yielded a colour that matched that of Na hydrogen carbonate indicating that the unknown compound contained Na. The anion trial for chloride proved to be positive, ensuing in the summing up that the unknown compound was sodium chloride.IntroductionThe group is employed by an Environmental Protection Agency to indentify a compound in the landfill in your place town. The group must besides detect as many chemical an d physical belongingss of the compound as we can. We need to invent two syntheses of the compound, and compare them for cost effectivity, safety, and possible output of the compound. To place the compound, the physical belongingss ( odor, colour, and province ) demand to be established. Next, the qualitative solubility of the compound was tested in H2O, methylbenzene, and propanone, which would find whether the compound would fade out from rain H2O or other chemicals that may be present in the landfill and make overflow. Conductivity was besides tested with a voltmeter in order to find whether or non the compound would be unsafe when dissolved in H2O. If the compound was conductive it would fade out in H2O and produce an electric current. The flame trial was performed to stipulate one of the elements. A solution of H2O and the component was used to put the nichrome wire in, and so the nichrome wire is placed into the fire. If the fire produces a colour it is declarative of a certain metalloid ion or metal. A colour is produced in the fire when the heat of the fire changes the metal ions into atoms which so become aroused and bring forth visible radiation that can be seen with the bare oculus. It is besides of import to analyse the presence of certain cations and anions utilizing trials that identify the presence of the anions chloride and sulphate, and the presence of the cation ammonium. The anion trials for chloride and sulfate prove to be positive when a white precipitate signifiers and the ammonium trial proves to be positive when an ammonium odor is produced. After all of the physical and chemical trials were performed, a solution of the unknown compound and a solution of what was deduced to be unknown compound were reacted with an acid ( azotic acid ) , a base ( potassium hydrated oxide ) , silver nitrate, K sulphate, and K nitrate in order to find if they produce the same consequences. Gravimetric filtration was so performed with the known and unknown s ubstance. A precipitate was formed utilizing Ag nitrate, which could so be weighed. After the filtration procedure, the unknown compound was so synthesized to bring forth a per centum output.ConsequencesTable 1 Physical Properties TestColor White State of Matter Solid Olfactory property None Solubility in Water Soluble Conduction 0.35 VsTable 2 Anion TrialsTrials PerformedConsequencesTrial for Chloride White Precipitate Formed Trial for Sulfate No Chemical reaction Trial for Nitrate No Brown Ring Trial for Carbonate Clear Trial for Acetate Clear, OdorlessTable 3 Cation TrialsTrials PerformedChemical reactionConsequencesTrial for Ammonium NH4Cl + NaOH i? Ammonium Smell No Odor Fire Test Bright Orange/Yellow Fire SodiumTable 4 Chemical reaction TrialsType of Chemical reactionBalanced EquationChemical reactionAcid NaCl ( aq ) + HNO3 ( aq ) – & A ; gt ; NaNO3 ( aq ) + HCl ( aq ) None Base NaCl ( aq ) + KOH ( aq ) – & A ; gt ; NaOH ( aq ) + KCl ( aq ) None Double Supplanting NaCl ( aq ) + AgNO3 ( aq ) – & A ; gt ; AgCl ( aq ) + NaO3 ( aq ) Precipitate formed Double Supplanting NaCl ( aq ) + K2SO4 ( aq ) – & A ; gt ; Na2SO4 ( aq ) + 2 KCl ( aq ) None Double Supplanting NaCl ( aq ) + KNO3 ( aq ) – & A ; gt ; NaNO3 ( aq ) + KCl ( aq ) NoneTable 5 Gravimetric AnalysisNaCl ( aq ) + AgNO3 ( aq ) – & A ; gt ; AgCl ( s ) + NaNO3 ( aq ) Vacuum Filtration Trial # Sum of Precipitate Produced ( gms ) Percent Output Known Trial 1 1.081 88.18 % Known Trial 2 1.196 97.56 % Unknown Trial 1 1.211 98.78 % Unknown Trial 2 1.185 96.66 % Unknown Trial 3 1.170 95.44 %Table 6 Synthesis Chemical reactionChemical reaction Sum Produced ( gms ) Theoretical Output ( gms ) Percent Output HCl ( aq ) + NaOH ( aq ) i? NaCl ( s ) + H2O ( cubic decimeter ) 1.971 2 98.55 %DiscussionFirst, the physical belongingss of the unknown compound were observed and recorded. It was found that the compound was crystalline in construction, a solid, white, with no olfactory property ( Table 1 ) . All of these belongingss suggest that the compound was ionic because ionic compounds do non hold a distinguishable olfactory property and are solid at room temperature because of their high thaw points. The unknown compound was so tested for solubility in H2O, methylbenzene and propanone. The compound was soluble in H2O, bespeaking the compound was a polar or ionic compound, and non soluble in methylbenzene or propanone which eliminates it being polar or nonionic. Therefore, this points to the compound being ionic. After the compound was dissolved in H2O, the conduction was tested with a voltmeter, which produced a electromotive force of 0.35 Vs turn outing that the substance is conductive since it is over 0.1 Vs. This farther proves that the unknown compound was io nic since merely ionic compounds dissociate in H2O and make an electric current. The fire trial was performed to find one of the elements in the compound. Four known compounds, Na hydrogen carbonate, Mg nitrate, Ca sulphate, and K nitrate were put under the fire trial to compare the unknown to. When the unknown compound was put under the fire trial it produced the same colour as Na hydrogen carbonate, bright orange/yellow, bespeaking the presence of Na ( Table 3 ) . The ammonium trial was besides performed to verify that the compound did non incorporate ammonium hydroxide. No odor was produced when the unknown solution and Na hydrated oxide were assorted, and a odor would bespeak the presence of ammonium hydroxide. Therefore, the compound was proven to incorporate Na. When the anion trials for chloride and sulphate were performed, a white precipitate was produced from the chloride trial, bespeaking the presence of chloride while the sulfate reaction created no precipitate bespeaking the absence of sulphate ( Table 2 ) . In add-on, the unknown compound was put through a series of reactions along with what was believed to be the compound in order to compare the reactions to find if they produce the same reactions. First Na chloride, what is believed to be the unknown compound, and the unknown compound were reacted with Ag nitrate, which produced a precipitate because it was a dual supplanting that produced AgCl which is non soluble in H2O. Sodium chloride and the unknown compound were reacted with K sulphate but produced no reaction because the merchandises sodium sulphate and K chloride are both soluble in H2O. Sodium chloride and the unknown compound were so besides reacted with K nitrate, making a dual supplanting reaction which produces Na nitrate and K chloride, which are besides both soluble in H2O, hence bring forthing no reaction. When Na chloride and the unknown compound were reacted with an acid, azotic acid, but the presence of the Na chloride did non impact the pH of the azotic acid becaus e it was an ionic compound. When the Na chloride and the unknown compound were reacted with a base, K hydrated oxide, there was besides no reaction or alteration in the pH of the K hydrated oxide because the Na chloride is an ionic compound. Both the Na chloride and the unknown compound produced the same consequences in every reaction further turn outing that they are one in the same ( Table 4 ) . Once it was found that Na chloride and Ag nitrate bring forth a precipitate when reacted, the reaction was used to bring forth a certain sum of precipitate which was so used in hydrometric analysis to see if both the known and unknown compound would bring forth the same sum of precipitate. The reaction that was filtrated was NaCl ( aq ) + AgNO3 ( aq ) – & A ; gt ; AgCl ( s ) + NaO3 ( aq ) . The consequences from the known reaction were 1.77 gms of filter paper and 1.081 gms of precipitate entirely, while the theoretical output was 1.225 gms. The unknown reaction has yet to be found. The per centum output for the reaction was 97.56 % ( Table 5 ) . A synthesis reaction was the concluding trial preformed. The undermentioned chemical reaction occurred: HCl ( aq ) + NaOH ( aq ) i? NaCl ( s ) + H2O ( cubic decimeter ) . Once all of the H2O was evaporated out with the usage of a hot home base, the precipitate was able to be weighed and the per centum output could be calculated. The reaction had a percent output of 98.55 % ( Table 6 ) .DecisionAfter being employed by the Environmental Protection Agency, the group was able to place the compound in the landfill. After all of the trials and reactions were performed, it was found that the unknown compound was sodium chloride. Its solubility in H2O, conduction, and crystalline construction points to the fact that the compound is ionic. The positive fire trial for Na indicates that Na is one of the elements in the compound because it produced a bright orange fire. The positive chloride trial, when a white precipitate was formed, indicates that chloride is the 2nd component in the compound. The unknown compound and Na chloride were put through the same reactions and systematically produced the same consequences, farther indicating that the unknown compound is sodium chloride. The gravitative analysis of the known and unknown substances provided similar consequences, endorsing up that the unknown substance was sodium chloride. The synthesis reaction produced a percent output of 95.05 % .Experimental Procedure:Physical Properties TrialsThe physical province of the unknown compound was observed. This included the province of affair, odor ( utilizing the wafting technique ) , colour, and construction. A little sum of the unknown compound was placed in about 50mL of H2O and stirred to see if it would fade out. The same solution was used for the voltmeter and the conduction was recorded.Anion TrialsChloride Ion TestApproximately 1 milliliter of the unknown solution was placed in a trial tubing and 1 milliliter of 6 M HNO3 was added. After that another 1 milliliter of AgNO3 was added. Whether a white precipitate was formed or non was recorded. If a white precipitate is observed, a chloride ion is present in the solution.Sulfate Ion TestApproximately 1 milliliter of the unknown solution was placed into a trial tubing and 1 milliliter of 6 M HCl was added. After that another 1 milliliter of BaCl2 solution was added to the same trial tubing. Whether or non a white precipitate formed was recorded. If a white precipitate is formed, sulphate is present in the solution.Cation TrialFire TestThe heat from the Bunsen fire was used to cleanse the nichrome wire. A little sum of the unknown compound was placed onto the nichrome wire and held over the fire. The colour of the fire was observed.Ammonium TrialApproximately 1 milliliters of 6 M NaOH was added to 1 milliliter of the unknown compound solution. The pennant technique was used to observe if there was any olfactory property. If the odor of ammonium hydroxide was present, there were ammonium ions nowadays in the solution.Responsiveness TrialsChemical reaction with an AcidA solution with a little sum of unknown compound was assorted in 50 milliliter of H2O and a separate solution of a little sum of ammonium chloride and 50 milliliter of H2O. A little sum of the two solutions were placed in to two separate trial tubings and a little sum of HNO3.Double Displacement Chemical reactionA solution of a little sum of unknown compound was placed into 50 milliliter of H2O and a separate solution incorporating a little sum of Na chloride and 50 milliliter of H2O. A little sum of the two solutions wa s placed into two separate trial tubings and a little sum of K2SO4 was added into each trial tubing. The trial tubings were so swirled and assorted.Double Displacement Chemical reactionA solution of a little sum of unknown compound was assorted with a solution of 50 milliliter of H2O and a separate solution of a little sum of Na chloride and 50 milliliter of H2O. A little sum of the two solutions were placed into two separate trial tubings and a little sum of AgNO3 was added into each of the trial tubing. The trial tubings were so swirled and assorted.Double Displacement Chemical reactionA solution of a little sum of unknown compound was assorted in 50 milliliter of H2O and a separate solution of a little sum of Na chloride and 50 milliliter of H2O. A little sum of the two solutions were so placed into two separate trial tubings and a little sum of KNO3 was added to each trial tubing. The trial tubings were so swirled and assorted, and whether or non a reaction occurred was recorded .Chemical reaction with a BaseA little sum of unknown compound was assorted with 50 milliliters of H2O and a separate solution of a little sum of ammonium chloride and 50 milliliter of H2O. A little sum of these two solutions were so placed into two separate trial tubings and a little sum of KOH was added.Hydrometric AnalysisA Buchner flask was used with a funnel placed over the top. The filter paper was weighed and so wetted with H2O somewhat. The solution incorporating the precipitate was poured onto the filter paper and left until most of the liquid had seeped through. The filter was so removed from the funnel and placed into an oven for 10 proceedingss until the precipitate and paper had wholly dried. The filter paper was so weighed with the precipitate still on top. The weight of the filer paper was subtracted from the new weight to obtain the most accurate consequence. The process was completed three times with the unknown substances and twice with a known substance.Synthesis Chemical reactionApproximately 12.3 milliliters of ammonium hydrated oxide was assorted with 6.2 milliliters of hydrochloric acid in a beaker. The solution was placed on a hot home base ( under a goon ) and allowed to boil until all of the liquid evaporated. The staying precipitate was removed from the beaker and weighed.