In this lab we worked with limiting and excess reagents. In these types of reactions we are able to tell which reactant will run out first. In this particular experiment we worked with copper (III) nitrate and potassium iodide to find out which are the limiting and excess reactants. To calculate the efficiency of a reaction chemists calculate the percent yield, which using the actual yield and theoretical yield. The actual yield tells us how much product you get after carrying out the reaction. The theoretical yield is the calculation of how much product you actually get. This ratio tells us how efficient the reaction was. Precipitation is the formation of an insoluble solid in a solution. We use a centrifuge to better separate the liquid and solid in the test tube. The centrifuge spins the test tube at a high velocity, which causes them to separate, and makes the liquid less cloudy. To separate the liquid and solid we draw the supernatant out using a pipette, and draw the liquid out carefully not to disturb the precipitate. The objectives in this experiment were to determine the lim...
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.).
The most important concept that should be taken from this lab is that the limiting reactant restricts the amount of product possible from a reaction. Increasing the amounts of other reactants will not increase the amount of product, but increasing the amount of the limiting reactant will.
This process allows us to determine the reaction order. When changing the concentration of the one particular reactant we are able to calculate the order based on the change in reaction rate.
Put 1mL of 0.1M cobalt (II) chloride hexahydrate dissolved in 95% ethanol into a test tube. Then add 1mL of deionized water. Tap the end of the test tube to mix the solution and record the pertinent data in section 2 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.
This is an experimental lab that tested if drinking water passes the United States maximum phosphate standard. The results of this lab can help the American who drink the water know if there are too much phosphate in the water. Each group made a Potassium phosphate dilution from a stock solution. The concentration of the solution that needed to made affected the amount of Potassium phosphate that was diluted. To create a calibration curve, each group used the different concentrated Potassium phosphate solutions in their test. The lab utilized a spectrophotometer to figure out the absorbance of the five different Potassium phosphate solution and the absorbance of an unknown concentration solution. The absorbance of the unknown solution was used
Through the completion of this experiment, the dynamics of stoichiometry are demonstrated by preforming a chemical reaction in a solution. This procedure will ultimately show how limiting reactants are factored into a reaction by using a varying amount of reactants involved. To better understand this concept, it is vital to define stoichiometry; stoichiometry is a way of documenting the amounts of products and reactants involved through a series of coefficients that describes the ration in which the reactants will fuse together and the products form. In this particular lab, the following formula will be used to preform the necessary calculations:
The Iodine Clock Investigation Introduction This is an investigation into the rate of a reaction and the factors that contribute to how fast a reaction will take place. Through the recording and analysis of raw data, this investigation also allows us to apply generally accepted scientific rules and to test them against results gained from accurate experimental procedures. Aim The aim of this experiment is to investigate the rate at which iodine is formed when the concentration and temperature of the reactants are varied, and to attempt to find the order and activation energy. The Chemistry 'THE IODINE CLOCK' - This is the experiment that will be used to investigate reaction rates, and it is a reaction between acidified hydrogen peroxide and potassium iodide: 2H+(aq)
Although the majority of the copper remained within the beaker, some of the copper went along with the supernatant liquid that was removed. Since some copper molecules were inadvertently removed from the beaker, the overall weight of the copper later measured less than what it should have been. Another laboratory error was how zinc was not fully extracted from the solution. While taking out the zinc that was used to separate the copper ion from the chlorine ion, some residue could have been left behind. As a direct result of stirring around the solid zinc to knock off the copper, some zinc from the original piece broke off. Not knowing how much zinc was left behind likely caused the weight of the later measured copper to be greater than what it should have been. Overall, the weight variation of the copper sample, after the procedure, was not 100% accurate since it gain weight from zinc and loss some weight due to
For this experiment you have to have a basic understanding of Collision Theory to understand what’s going on in the experiment. Collision Theory is a model of chemical reactions in which a reaction occurs after a collision containing enough energy occurs between two reactant molecules. This model has five factors which can be affected and they are the nature of reactants, temperature, concentrations, surface area and catalyst. If one of these were changed then the reaction could occur faster or slower depending on what was changed.
Chemical kinetics is the study of rates of chemical processes with respect to reaction rates, result of differing variables, re-arrangement of atoms, formation and intermediates etc (Theodore L. Brown,2010)(Chung Chieh,2016). The study of chemical kinetics is one that is a major importance in chemical research. It is powerful research tool in determining the reaction mechanism of several different reactions in chemistry(The University of Sydney,2002).
When conducting Part B, formation of precipitate, change in color, difference in temperature and gaseous reactions all took place. However unlike Part A more responsive results were recorded.
These coefficients can also determine the relative number of molecules, formula units, along with the moles involved in a chemical reaction. (Oklahoma City Community College, n.d.). Based on the experimental data, the mole ratio of limiting reagent to precipitate is 1 where the moles of the limiting reagent is 4.717426×10-3 moles and by multiplying by the ratio obtained from the balanced equation, the moles of the precipitate also 4.717426×10-3 moles. When we compare this to the ratio found within the balanced equation it is observed that the ratio is 1mol/1mol=1 or 1:1. Similarly through the experimental data, the ratio is 4.717426×10-3mol/4.717426×10-3mol = 1 again this is also 1:1. This indicates that for every one mole of the limiting reagent there is one mole of the precipitate, for every two moles of the limiting reagent there is two moles of the precipitate, and so
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:
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.
One vital process in the human body observed in chemistry is the idea of chemical kinetics. Chemical kinetics is the study of the rate of reactions, or how fast reactions occur.1 Three factors that affect chemical kinetics are concentration, temperature, and catalysis. As the concentration of a substance increases, the rate of the reaction also increases.1 This relationship is valid because when more of a substance is added in a reaction, it increases the likelihood that the