Through the experimentation of reactions between iron (III) nitrate and potassium thiocyanate, as well as cobalt (II) chloride hexahydrate in water, equilibrium systems disturbed by stress (changing the amount of reagents and temperature) will shift in order to minimize the stress. Therefore, if the concentration of reactant increases, the rate of the forward reaction will increase and equilibrium will reestablish when the concentration of products increase (vice versa). This can be observed through color changes of the solutions. Equilibrium Constant Equations for Equilibrium System 1 Fe3+ + SCN- ⇌ FeSCN2+ Yellow Orange + Colorless ⇌ Blood Red Orange Keq = [FeSCN2+] / [Fe3+][SCN-] Table 1: Equilibrium System 1 Part A Data Table studying the effects of concentration within a complex-ion equilibrium reaction between iron (III) nitrate and potassium thiocyanate. Substance Added Color of Substance Resulting Color of Solution Original - Potassium …show more content…
The original solution containing potassium thiocyanate is clear and colorless. However, when iron (III) nitrate or potassium thiocyanate is added to the solution, the overall color becomes darker and more concentrated to orange then to blood red. After a short time, the solution achieves equilibrium, but not at equal concentrations. By adding iron (III) nitrate or potassium thiocyanate, the amount of reagent increases, therefore the forward reaction increases in order to generate more product and increase the concentration of product. In the equilibrium constant equation, when increasing the amount of SCN-, the denominator increases, therefore Q < Keq. In order to reestablish equilibrium, concentration of products need to increase and the concentration of reactants have to decrease through the consummation of reactants and production of
This week’s lab was the third and final step in a multi-step synthesis reaction. The starting material of this week was benzil and 1,3- diphenylacetone was added along with a strong base, KOH, to form the product tetraphenylcyclopentadienone. The product was confirmed to be tetraphenylcyclopentadienone based of the color of the product, the IR spectrum, and the mechanism of the reaction. The product of the reaction was a dark purple/black color, which corresponds to literature colors of tetraphenylcyclopentadienone. The tetraphenylcyclopentadienone product was a deep purple/black because of its absorption of all light wavelengths. The conjugated aromatic rings in the product create a delocalized pi electron system and the electrons are excited
Compress the safety bulb, hold it firmly against the end of the pipette. Then release the bulb and allow it to draw the liquid into the pipette.
The purpose of the experiment is to study the rate of reaction through varying of concentrations of a catalyst or temperatures with a constant pH, and through the data obtained the rate law, constants, and activation energies can be experimentally determined. The rate law determines how the speed of a reaction occurs thus allowing the study of the overall mechanism formation in reactions. In the general form of the rate law it is A + B C or r=k[A]x[B]y. The rate of reaction can be affected by the concentration such as A and B in the previous equation, order of reactions, and the rate constant with each species in an overall chemical reaction. As a result, the rate law must be determined experimentally. In general, in a multi-step reac...
I did accomplish the purpose of the lab. First, I determined the percentage of water in alum hydrate, and the percentage of water in an unknown hydrate. The results are reasonable because they are close to the example results. Second, I calculated the water of crystallization of an unknown hydrate. Furthermore, I developed the laboratory skills for analyzing a hydrate.
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.
+ 2I¯ (aq) + H[-1] 2O2 (l) ÕI2 (aq) + 2H2O2 (aq) Iodide ions are firstly oxidised by the hydrogen peroxide, as shown in the above equation. The iodine that is then produced reacts immediately reacts with thiosulphate ions as follows: I2 (aq) + 2Na2S2O3 (aq) Õ 2NaI (aq) + Na2S406 (aq) As soon as all of the thiosulphate ions have reacted with the iodine, the excess iodine molecules react with the 2% starch solution that is present in the reaction. This can be seen as an instant change in colour, from a colourless solution, to a deep purple coloured solution. This change in colour denotes the completion of the reaction. Factors affecting the rate of reactions: All chemical reactions occur at a definite rate under particular conditions.
An elements¡¦ reaction to certain substances may be predicted by its placement on the Periodic Table of Elements. Across a period, an element on the left will react with more vigor than one on the right, of the same period. Vertically, as elements are sectioned into groups, the reaction of each element increases as you move down in the same group. With this in mind, the reactions of the substances involved in this experiment may be hypothesized, observed, and validated.
Abstract: This week we experimentally determined the rate constant k for the reaction 2HCl (aq) +Na2S2O3 (aq) → S (s) + SO2 (aq) + H2O (l) + 2NaCl (aq). In order to do this the average reaction time was recorded in seconds during two trials. The data from the experiment shows this reaction is in the first order overall: rate=.47s-1 [HCl]0 [Na2S2O3]1. These findings seem to be consistent with the expected results
The objective of this experiment is to study the continuous variations method that is used to determine the composition of the solution Ni2+ ethylenediamine complexes.
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
However, in order to measure the rates of reaction, sodium thiosulphate and starch are added. Sodium thiosulphate is added to react with a certain amount of iodine as it is made. Without the thiosulphate, the solution would turn blue/black immediately, due to the iodine and starch. The thiosulphate ions allow the rate of reaction to be determined by delaying the reaction so that it is practical to measure the time it takes for the iodine to react with the thiosulphate. After the all the thiosulphate has reacted with the iodine, the free iodine displays a dark blue/black colour with the starch. If t is the time for the blue/black colour to appear, then 1/t is a measure of the initial rate.
== == I completed a table to show my results, here is the table: Table 1. Results of different changes of substances Part A Copper (II) Sulfate and Water Reactant description Water (reactant): Color: Colorless Transparency:
The first experiments investigate the order of reaction with respect to the reactants; hydrogen peroxide, potassium iodide and sulphuric acid by varying the concentrations and plotting them against 1/time. An initial rate technique is used in this experiment so ‘the rate of reaction is inversely proportional to time.’ To find the order of reaction in respect to the reactants, 1/time is plotted against the concentration of Hydrogen Peroxide using the equation:
The purpose of the experiment is to identify and understand reactions under kinetic and thermodynamic control. A reaction under kinetic and thermodynamic control can form two different types of products. A reaction under kinetic control is known to be irreversible and the product is formed quickly. A reaction under thermodynamic control is known to require rigorous conditions. It is also reversible. The final product is more stable than the product made by kinetic control. The chart below shows the two types of reaction coordinates:
The actual, theoretical, and percent yield of sodium chloride was found. Sodium Carbonate was mixed with hydrochloric acid and the liquid was boiled until there was nothing left. The result was the production of salt, or sodium chloride.