Introduction: A precipitation reaction can occur when two ionic compounds react and produce an insoluble solid. A precipitate is the result of this reaction. This experiment demonstrates how different compounds, react with each other; specifically relating to the solubility of the compounds involved. The independent variable, will be the changing of the various chemical solutions that were mixed in order to produce different results. Conversely the dependent variable will be the result of the independent variable, these include the precipitates formed, and the changes that can be observed after the experiment has been conducted. The controlled variable will be the measurement of ten droplets per test tube. Purpose: To predict and the test, …show more content…
Cations are positively charged ions, which are attracted to their negatively charged counterparts, anions. Precipitates can form when these cations and anions combine in aqueous solutions; however, precipitates only form if one of the products of the chemical reaction is not soluble in that solution. Solubility is instrumental in understanding how precipitation reactions occur. This is because solubility rules, determine whether a precipitate can form. A precipitate can form if the cation in the compound is soluble when combined with an anion. For example when the solutions silver nitrate and sodium chloride (reactants) are mixed, silver chloride and sodium nitrate (products) are formed. Following the solubility laws, silver nitrate is the precipitate, as it isn’t …show more content…
This can be done by first finding the products of the chemical reactions, which are found by swapping the anions on each reactant. Once this is done, predictions can be made. The table above, describes the solubility rules, these are used to decide whether a compound will be soluble, and then consequently to this reveal a precipitate. Barium sulfate for example is insoluble and if it was to be mixed with an aqueous compound, barium sulfate would be the precipitate. This is an example of how a prediction can be made, without physically viewing the experiment or given the results. It is also a way of identifying what the precipitate is once the experiment has been
The purpose for this experiment was to determine why it was not possible to obtain a high percent yield when Calcium Nitrate Ca(〖NO_3)〗_2 with a concentration of 0.101 M was mixed with Potassium Iodate KIO_3 with concentration of 0.100 M at varying volumes yielding Calcium Iodate precipitate and Potassium Nitrate. Filtration was used to filter the precipitates of the solutions. The percent yield for solution 1 was 87.7%, and the percent yield for solution 2 was 70.8%. It was not possible to obtain a high percent yield because Calcium Iodate is not completely soluble and some of the precipitates might have been rinsed back to the filtrates when ethanol was used to remove water molecules in the precipitate.
Thorough analysis of the graph displayed enough evidence suggesting that an increase in substrate concentration will increase the height of bubbles until it reaches the optimum amount of substrate concentration, resulting in a plateau in the graphs (figure 2). Hence; supported the hypothesis.
(Na+ and CL-) do not react to form a salt until the Water is formed
the ones that contains ppt in half, then add 6M NH3 to one set of them
3. Drop tablet of Alka-Seltzer into the cold beaker of water and time length of reaction with a stopwatch
The hydrolysis of salts can be determined on the basis of the strength of the acid or base which forms it. If the salt is formed from a strong acid and a strong base, such as NaCl, the salt will form a neutral solution, since the anions of the acid and the cations of the base will not react with the water. A salt from a weak base and a strong acid, with NH4Cl as an example, will form an acidic solution. This is due to the cations from the base that increase the hydrogen ion concentration, by donating protons, which is known as a Bronsted acid. When concerning a salt formed by a weak acid and a strong base, such as Na C2H3O2, a basic solution will form. The anions of a weak acid in water will generate hydroxide ions, since the molecule will accept protons. It is termed as a Bronsted base. Though no examples were present, the salt that forms from a weak acid and a weak base can be determined by comparing the Ka (cation) and the Kb (anion) values. Most metallic ions, those found in groups 1A and 2A on the periodic table, such as Ca2+, a strong base, will have no reaction with water. However, all other metallic ions will undergo hydrolysis to form an acidic solution, such as KAl (SO4)2. As the Al is the molecule that was hydrolyzed, the spectator ions would not be present in the hydrolysis reaction, as is shown in the net ionic equations
Solubility is defined as the maximum amount of a substance that will dissolve in a given amount of another substance at constant temperature and pressure. Solubility is typically expressed in terms of maximum volume or mass of the solute that dissolve in a given volume or mass of a solvent. Traditionally the equilibrium solubility at a given pH and temperature is determined by the shake flask method. According to this method the compound is added in surplus to a certain medium and shaken at a predetermined time. The saturation is confirmed by observation of the presence of un-dissolved material. Saturation can also be reached if the solvent and excess solute is heated and then allowed to cool to the given temperature. After filtration of the
Since Barium (Ba2+) is the only cation in this experiment which has this property, it was determined that the cation for this solution must be Ba2+. The solution was determined to be neutral, based on the litmus test results in Table 2. The anions which form a precipitate with Ba2+ were identified to be Cl-, NO3-, and SO42- using Table 4. Since precipitate was observed to be formed between solution B and solutions C,D, and F in the experiment, the possible anions were compared to determine which one followed these properties. Using the information in table 4, Cl- was declared the anion evident in solution B. Therefore, the solution B must be
For this experiment we have to use physical methods to separate the reaction mixture from the liquid. The physical methods that were used are filtration and evaporation. Filtration is the separation of a solid from a liquid by passing the liquid through a porous material, such as filter paper. Evaporation is when you place the residue and the damp filter paper into a drying oven to draw moisture from it by heating it and leaving only the dry solid portion behind (Lab Guide pg. 33.).
During week 1 of this experiment, we recorded common components of fertilizers and then went on to find the chemical formulas involved in creating them. The second week we began the process of comparing three authentic ions we had established in the first week to ion samples to discover other properties they might contain. We decided to discover these different ingredients by preforming a serious of tests, which included placing 0.2g solid of both the authentic and the sample fertilizer separately, in order to establish a constant, and dissolved the fertilizer in 20 mL of water, then checked to see if Mg was present in the sample solution. By setting up a constant and preforming a methodical experiment all on the samples given, we demonstrated the ability to correctly establish and preform an experiment and solve the problem at hand, which was distinguishing the contents of the authentic
In our experiment we utilized the hydrate cobaltous chloride. Hydrates are crystalline compounds in which one or more molecules of water are combined with each unit of a salt. Cobalt (II) chloride hexahydrate is an inorganic compound which is a deep rose color in its hydrated form. As an inducer of
Determination of thermodynamic values allows for analysis of what makes a reaction spontaneous. In this experiment, the equilibrium constant of the crystallization of potassium nitrate as it ionized in water was found and used to determine enthalpy, entropy, and Gibb’s Free Energy of a reaction. The variables were found by by graphing the solubility of potassium nitrate as a function of time and by utilizing relationships based on the van’t Hoff equation. Based on the determined Ksp of 43.4 the average Gibb’s Free Energy over on six trials was -8.4834 kJ/mol with a 510 % error. Relations based on the graph of ln(k) vs. 1/T(K) showed the enthalpy of the reaction to be +34.78 kJ/mol yielding a 2.30% error, and showed the entropy to be +137.4
The purpose of this experiment was to prepare two solutions and use them to perform a precipitate reaction. Then using the results and mass gathered from the experiment, to determine the limiting reagents and to calculate percent yield.
We attached a gas syringe via a plastic tube to a test tube and used a
borate) and 1.0 g. of sodium hydroxide in 20 mL of warm water. It may