Chemical equilibrium lab report sample


This lab focused on the concept of equilibrium and how it can be shifted either to the left or to the right by adding or removing parts of the equation. Chemical equilibrium can be understood as when the forward reaction is equal to the reverse reaction. The goal of the experiment was to see this equilibrium by observing the color change and determining what color changes mean in terms of the reaction and equilibrium of the reaction.

The concept can be better understood by realizing that the system will balance the equilibrium when another chemical or substance is added to it.

When the system reaches equilibrium, it will not come out of it. Equilibrium is represented by a double arrow between the reactants and products, meaning that the formation of reactants and products is constant.

During the lab, there were many substances that were added to systems to observe the equilibrium. When the substances are added, the system is interrupted, so the equilibrium is shifted to one side of the reaction, which depends on the substance that is added.

The principle states that when the system is changed, the chemicals will try to keep it balanced again. Observing changes within the system is observing the system shift to one side of the reaction, then coming back to equilibrium once again. Experimental Procedure: This experiment was started by preparing a stock solution of 1 ML iron III chloride, potassium thiocyanate and 50 mL of distilled water.

The stock solution was split into 4 test tubs and the first tub was used as a control then 1 mL of iron III chloride was added to the second tub and 1 mL of potassium thiocyanate was added to the third tub. Afterwards the solution was split in two and iron III chloride drop-wise to one of the test tubs using the other as a comparison. Then In part B of the lab mL of potassium chromate was added to a test tub. In part C of the experiment 2 mL of cobalt chloride was added in 2 test tubs.

Modeling Chemical Equilibrium

This website uses cookies to ensure you have the best experience. Got it! Learn more. The rate of diffusion can differ greatly due to the temperature of which something is diffusing from.

Diffusion is the process of something being spread or dispersed. The life of cells depends on the dispersion or movement of chemicals throughout the cell. During the process of diffusion. Physics Lab Report - Pendulums and More - qcc phyics lab - lab report words - 4 pages depends on the amplitude of the pendulum. Because of this we can apply the simple harmonic equations to this experiment. A bob was attached to one end of the string and released from different starting points.

The point.As we saw in the previous section, reactions proceed in both directions reactants go to products and products go to reactants. We can tell a reaction is at equilibrium if the reaction quotient Q is equal to the equilibrium constant K. We next address what happens when a system at equilibrium is disturbed so that Q is no longer equal to K.

If a system at equilibrium is subjected to a perturbance or stress such as a change in concentration the position of equilibrium changes. Since this stress affects the concentrations of the reactants and the products, the value of Q will no longer equal the value of K.

However, if we have a mixture of reactants and products that have not yet reached equilibrium, the changes necessary to reach equilibrium may not be so obvious. In such a case, we can compare the values of Q and K for the system to predict the changes.

A chemical system at equilibrium can be temporarily shifted out of equilibrium by adding or removing one or more of the reactants or products. The concentrations of both reactants and products then undergo additional changes to return the system to equilibrium.

The effect of a change in concentration on a system at equilibrium is illustrated further by the equilibrium of this chemical reaction:. The numeric values for this example have been determined experimentally. This gives:. We have stressed this system by introducing additional H 2.

The stress is relieved when the reaction shifts to the right, using up some but not all of the excess H 2reducing the amount of uncombined I 2and forming additional HI. Sometimes we can change the position of equilibrium by changing the pressure of a system. However, changes in pressure have a measurable effect only porno kino mogol heleer systems in which gases are involved, and then only when the chemical reaction produces a change in the total number of gas molecules in the system.

An easy way to recognize such a system is to look for different numbers of moles of gas on the reactant and product sides of the equilibrium. While evaluating pressure as well as related factors like volumeit is important to remember that equilibrium constants are defined with regard to concentration for K c or partial pressure for K P.

Some changes to total pressure, like adding an inert gas that is not part of the equilibrium, will change the total pressure but not the partial pressures of the gases in the equilibrium constant expression. Thus, addition of a gas not involved in the equilibrium will not perturb the equilibrium. Check out this link to see a dramatic visual demonstration of how equilibrium changes with pressure changes. As we increase the pressure of a gaseous system at equilibrium, either by decreasing the volume of the system or by adding more of one of the components of the equilibrium mixture, we introduce a stress by increasing the partial pressures of one or more of the components.

The reverse reaction would be favored by a decrease in pressure. Consider what happens when we increase the pressure on a system in which NO, O 2and NO 2 are at equilibrium:. The formation of additional amounts of NO 2 decreases the total number of molecules in the system because each time two molecules of NO 2 form, a total of three molecules of NO and O 2 are consumed. This reduces the total pressure exerted by the system and reduces, but does not completely relieve, the stress of the increased pressure.

On the other hand, a decrease alb ingress controller the pressure on the system favors decomposition of NO 2 into NO and O 2which tends to restore the pressure. Because there is no change in the total number of molecules in the system during reaction, a change in pressure does not favor either formation or decomposition of gaseous nitrogen monoxide.

Changing concentration or pressure perturbs an equilibrium because the reaction quotient is shifted away from the equilibrium value. Changing the temperature of a system at equilibrium has a different effect: A change in temperature actually changes the value of the equilibrium constant. Increasing the temperature of the reaction increases the internal energy of the system.

Thus, increasing the temperature has the effect of increasing the amount of one of the products of this reaction. The reaction shifts to the left to relieve the stress, and there is an increase in the concentration of H 2 and I 2 and a reduction in the concentration of HI.A reversible reaction is a reaction in which both the conversion of reactants to products forward reaction and the re-conversion of products to reactants backward reaction occur simultaneously:.

Thus over time the forward reaction slows down. Eventually a point will be reached where the rate of the forward reaction will be equal to the rate of the backward reaction.

When this occurs, a state of chemical equilibrium is said to exist. Chemical equilibrium is a dynamic state. A reversible reaction at equilibrium can be disturbed if a stress is applied to it.

Examples of stresses include increasing or decreasing chemical concentrations, or temperature changes. If such a stress is applied, the reversible reaction will undergo a shift in order to re-establish its equilibrium. Eventually the forward reaction would slow down and the forward and backward reaction rates become equal again as the system returns to a state of equilibrium.

Using similar logic, the following changes in concentration are expected to cause the following shifts:. In other words, if a chemical is added to a reversible reaction at equilibrium, a shift away from the added chemical occurs. When a chemical is removed from a reversible reaction at equilibrium, a shift towards the removed chemical occurs. A change in temperature will also cause a reversible reaction at equilibrium to undergo a shift.

The direction of the shift largely depends on whether the reaction is exothermic or endothermic. In exothermic reactions, heat energy is released and can thus be considered a product. In endothermic reactions, heat energy is absorbed and thus can be considered a reactant.

In this lab, the effect of applying stresses to a variety of chemical systems at equilibrium will be explored.

The equilibrium systems to be studied are given below:. By observing the changes that occur color changes, precipitate formation, etc. Equipment: 10 small test tubes, test tube rack, test tube holder, Bunsen burner, 2 medium-sized beakers for stock solutionsmL graduated cylinder, wash bottle, stirring rod, and scoopula.

If any of these chemicals spill on you, immediately rinse the affected area under running water and notify your instructor. These spots will eventually fade after repeated rinses in water. Finally, in Part 4 you will be heating a solution in a test tube directly in a Bunsen burner flame. If the solution is overheated it will splatter out of the tube, so be careful not to point the tube towards anyone while heating. Record all observations on your report form. These should include, but not be limited to, color changes and precipitates.

Note that solution volumes are approximate for all reactions below. Dispose of all chemical waste in the plastic container in the hood.Having a chance to participate in chemistry lab is a good thing for people.

Based on the research, all the science majors always need to write a lab report after performing a certain experiment. Chemistry is a subject in which we all need to turn in the lab report the to teacher. Based on the lab report, the professor can see how his student understands and applies the lab to life.

When writing lab reports, there are certain formats and contents of the lab that must be followed in order to convey the.

Step 3 Color change and observations. Blue, the more HCl added, the more blue the flow network has gotten, along with being warmer Step 5 Color change and observations.

Pink, slowly turning from the top to the bottom. Step 6 Color change and observations. The test tube from step 5 is turning blue, and the one from step 3 stays to blue. Step 7 Color change and observations. The test tube from step 5 is going to be pink, and the one from step 3 turn pink. Step 8 Color Change and observations. Christian, G. Analytical Chemistry, 6th edition. Confirm the stoichiometry of the reaction. Background In the study of chemical reactions, chemistry students first study reactions that go to completion.

Inherent in these familiar problems—such as calculation of theoretical yield, limiting reactant, and percent yield—is. It was hypothesized that the greater the stronger the concentration gradient, the faster the rate of diffusion would be. To test this, dialysis tubes were submerged in different concentration fructose solutions.

We weighed the tubes at specific. The lab errors that occurred in this lab would be the heat escaping while the reactants were being added to the calorimeter because there is an opening and way for the heat to escape in that moment. This caused the reaction to lose heat and energy to the lab and cause the reaction to report less energy than there should be. Also, some of the heat was lost from the calorimeter because no perfect calorimeter. Report must not exceed three pages including this page.

Page limit does not include any attached spectra or references. The principle states that the equilibrium will shift in the direction that will minimize the effects of the change. This lab consists of two parts. We mixed these two solutions in a ml beaker. We added distilled water into the solution …show more content… 6.The students explain their examples of real world chemical equilibrium, including in our bodies.

The teacher demonstrates Le Chatelier's principle using a solution of tea, showing how different additives will change the tea's color and its equilibrium. The students prepare to do an experiment concerning the equilibrium of smog. Obtain, evaluate, and communicate information about the chemical and physical properties of matter resulting from the ability of atoms to form bonds. Develop a model to illustrate the release or absorption of energy endothermic or exothermic from a chemical reaction system depends upon the changes in total bond energy.

Obtain, evaluate, and communicate information about how to refine the design of a chemical system by applying engineering principles to manipulate the factors that affect a chemical reaction. Plan and carry out an investigation to provide evidence of the effects of changing concentration, temperature, and pressure on chemical reactions. Construct an argument using collision theory and transition state theory to explain the role of activation energy in chemical reactions.

Refine the design of a chemical system by altering the conditions that would change forward and reverse reaction rates and the amount of products at equilibrium. Le Chatelier's Principle - a principle that states that when the equilibrium of a system is disturbed or stressed, the system adjusts to reestablish equilibrium by minimizing or countering the stress.

The Haber Process - the process of synthesizing ammonia from nitrogen and hydrogen gases. The Chemistry Matters teacher toolkit provides instructions and answer keys for labs, experiments, and assignments for all 12 units of study. GPB offers the teacher toolkit at no cost to Georgia educators.

Complete and submit this form to request the teacher toolkit. You only need to submit this form one time to get materials for all 12 units of study. The focus of this unit is to help students understand the condition in which all competing influences counteract each other, resulting in a stable, balanced, or unchanging system. Tagged as: Education. Segment D: Le Chatelier's Principle. Chemistry Matters Unit Introduction to Equilibrium.

Support Materials. Vocabulary chemical equilibrium - a state that is reached when the rate of the forward reaction equals the rate of the reverse reaction. Teacher's Guide The Chemistry Matters teacher toolkit provides instructions and answer keys for labs, experiments, and assignments for all 12 units of study. Chemistry Matters Segments. Segment A: Chemical Equilibrium. Segment E: Smog Lab. Segment F: Smog Lab Results.This website uses cookies and similar technologies to deliver its services, to analyse and improve performance and to provide personalised content and advertising.

Information about your use of this website will be shared with Google and other third parties. Read our privacy policy. In association with Nuffield Foundation. This equilibrium can be disturbed by changing the chloride ion concentration or by changing the temperature.

The distinctive colours of the two cobalt II species in solution produce an attractive visual demonstration of a reversible reaction and the effect of concentration and temperature on the position of equilibrium. If students are unfamiliar with the formulae of complex ions this may confuse the issue. For the purposes of this discussion the equilibrium could adequately be represented by:.

A white background will help to show the colour changes to best effect. For big groups the reactions should be scaled up, using larger containers such romance novel wuxia novels measuring cylinders or beakers, to improve visibility.

The change in colour from blue to pink of the cobalt complexes here has been the basis of cobalt chloride indicator papers for the detection of the presence of water. It is also used in self-indicating silica gel desiccant granules. Adding concentrated hydrochloric added raises the chloride ion concentration, causing the equilibrium to move to the right, in accordance with Le Chatelier.

Adding water lowers the chloride ion concentration, moving the equilibrium in the opposite direction. As an extension it is possible to show that it is the Cl — ions in the hydrochloric acid that shift the equilibrium by adding a spatula of sodium chloride instead to the pink solution. This produces a bluer colour, but this may take some time because the salt is slow to dissolve. This collection of over practical activities demonstrates a wide range of chemical concepts and processes.

Each activity contains comprehensive information for teachers and technicians, including full technical notes and step-by-step procedures. Use this practical to investigate how solutions of the halogens inhibit the growth of bacteria and which is most effective. Site powered by Webvision Cloud. Skip to main content Skip to navigation. Four out of five 1 Comment. The demonstration could also be adapted for use as a class experiment with suitable groups. Time taken should be about 10 minutes. As cobalt II chloride is a skin sensitiser, take care to avoid skin contact and wash hands well after use.Equilibrium is a challenging topic for high school chemistry students to understand.

This year I decided to tackle the conceptual understanding of equilibrium first with three different analogies and a Process Oriented Guided Inquiry Learning POGIL activity before even mentioning the words "equilibrium expression". The outcome was very positive from my perspective. With a firm grasp on the concept of equilibrium, the application of the mathematical description of a system was easier for my students to master.

I likened understanding chemical equilibrium with taking the red pill because you have to open your eyes to the real world of chemistry. We can no longer pretend that every reaction goes all the way to completion!

Maybe this scared the volvo epc more than amused them, but it set the stage with a little humor and a bit of anticipation of what was to come. Photo 1: Water transfer equilibrium analogy: notice the transfer beakers are different in size. Periodically we tested to see if we had reached equilibrium by measuring the volume of water transferred in each direction. When equilibrium is reached in the simulation, the different-sized beakers both scoop up the same volume due to the water level in each bowl.

The goal of this demonstration was to help my students understand that equilibrium is reached when the forward and reverse rates are equal, not when the amount of reactant and product are equal.

With this conceptual understanding in their grasp, the students were ready to put some numbers to another water transfer equilibrium analogy. Next they conducted the classic experiment with two same-sized graduated cylinders and two different sized straws.

Equilibrium concept through interactive analogies

Using their index fingers, students pipetted colored water using drinking straws from one graduated cylinder to the other Photo 2. After each transfer between reactants and products, the volume of water was measured in each cylinder Photo 3. McDonalds has really large straws that are perfect for this activity.

Students were instructed to put the straws to the very bottom of each cylinder to get accurate results. The result was a beautiful graph of the concentration of the "reactants" and "products" as they approach equilibrium Fig. It took about 12 transfers for the system to reach equilibrium, which was just about all the patience my students had for the water transfer using drinking straws. At equilibrium the volumes are different in each cylinder — one approximately Once again, the conceptual understanding of equilibrium was reinforced with this experiment, with the addition of a graphical treatment of the data.

Equilibrium demonstration: Straw transfer: Reaction simulation reaching equilibrium using different-sized straws transferring volume from one cylinder to another. Using the graph of their data, students calculated the ratio of reactants to products after each transfer. By comparing the value of this ratio, the students begin to see how the ratio changed until equilibrium is established.

Photo 3: Checking the volumes after each transfer. Equilibrium has not been reached. The next table shows the first three rounds in the pennies activity. The initial conditions of the system are shown in the first entry. They tried using more reactants, all products and no reactants, as well as an even split between products and reactants. Purpose: The shift in equilibrium position of a chemical reaction with applied stress is LABORATORY REPORT: Use the Report form for this experiment.

Lab Report Chemical Equilibrium: Reversible Reactions Vanier And Chemistery Sec5 Report

Purpose: The shift in equilibrium position of a chemical reaction with applied stress and LABORATORY REPORT: Use the Report form for this experiment. Free Essay: Introduction Equilibrium is the concept that in a chemical reaction where both the forward and reverse reactions occur, equilibrium is reached.

Results 1. In your results for each section, describe the chemical changes that these color changes reflect in the table below. For example, using the. When this occurs, a state of chemical equilibrium is said to exist. reaction already at equilibrium: A+B−⇀↽−C+D. If, for example. Background: Not all reactions go to completion, or use up all of one of the reactants. In some chemical reactions there is always some amount of products. Aim: The aim of the lab “Chemical Equilibrium” is to observe the effects of changes in concentrations of products and reactants on the position of the.

For example (select one from each underlined section)If the amount of reactant increases, the rate of the forward reaction will increase to reach a. Examples of stresses include increasing or decreasing chemical concentrations, or temperature changes. If such a stress is applied, the reversible reaction will. Chemical Equilibrium Lab Report Essay Words. Experiment 8 DETERMINATION OF AN EQUILIBRIUM CONSTANT.

Experiment 1 Chemical. Equilibria and Le Châtelier's. To gain practice calculating an equilibrium constant. Introduction. Many chemical systems are considered to be reversible. For example, drop the temperature. Introduce the topic of chemical equilibrium with a demonstration showing the Students can use the Laboratory Report Format to write their lab reports.

Appendix C: An Analogy for an Equilibrium Reaction: Lab Report. Checklist Appendix Equilibrium and Le Châtelier's Principle (Pre-lab) Post lab questions will ask you to use Le Chatelier's theory to explain your observations, and to use these results to establish whether the reaction is.

A spectrophotometer emits a beam of light through a sample and then measures the intensity of light through the solution. This information can be used to. Since the calculations that are necessary to find Keq may not be apparent, let us consider a specific example. Assume that we prepare our solution by mixing. Final Report: Group 3 EXPERIMENT 3: CHEMICAL EQUILIBRIUM; LE CHATELIER'S PRINCIPLE.

product of the reactant concentrations at chemical equilibrium (each concentration raised to a ]eq in sample solutions from absorbance measurements. Easy to deliver and quick to achieve results. CA Chemistry Content Standards: 8a, 8b, 8c, 6d, 5f*, 3e*. 7. Thermodynamics and Equilibrium (using Rubber Bands). The lab presents this kirvens in the basic format of: Explain the concept of chemical equilibrium; Distinguish between static and dynamic equilibrium.