CHE 105 – Week 6 Formative Assessment. Instructions: • • • • • Each student will work on this assignment alone. Assignments with identical answers will earn grades of zero. If you have questions, you are to ask me, your instructor, not your peers. The assessment will be printed out, completed, scanned, or photographed and uploaded to the upload area. Only assignments uploaded to the class will be graded. You must show ALL work. Submissions with answers only will not be evaluated. Formats: The following formats will be evaluated: • Microsoft Word Note: if you cannot scan your work before submitting, you are welcomed and encouraged to do the following: • • • • Take an image of each page of your work with your phone. Copy/paste those images to a Word document. Make sure the image size is the same as the page. Submit one image per page. Save the file as a Word document. Submitted files in the following formats will NOT be evaluated: • Pages • Lone Jpeg images • Any other file formats *********************************************** The Week 6 Formative Assessment Assignment will test your understanding of colligative properties. Le Chatelier’s Principle Formative Assessment Part 1: Application: This formative assessment involves study of equilibrium and Le Chatelier’s Principle. This lesson is designed to provide examples that will enable you to understand concept of equilibrium and what causes it to shift to the right or to the left. Specifically, the assessment is designed to dispel the notion that equilibrium in a chemical reaction implies equal amounts of reactants and products. Nothing could be farther from the truth! Equilibrium, in reality, exists in all situations in chemistry and chemical reactions, because all processes are, to some degree, reversible. Whenever the temperature, concentration of reactants or products, or partial pressure of various components of the reaction are changed, Le Chatelier’s Principle applies, and equilibrium will shift toward the reactants or products in a way that will resolve the stress on the system. Once a reaction reaches equilibrium, the rates (speed of change) of the forward and backward reactions are equal, but the amounts of reactants and products are usually unequal. Equilibrium is reached when the ratio of reactants and products is the most stable. When a stress is placed on a system which is at equilibrium, the system acts in a way to counteract that stress and restore equilibrium. The stress causes a new equilibrium. This week we have studied Le Chatelier’s Principle. Items needed to complete this assignment: • • • This document Two clear glasses of the same size Water Before we begin, please print out this Formative Assessment, and address the following questions: 1. Based on your understanding at this moment, provide an example of equilibrium: a system which is not changing. Propose a stress which might change the system. 2. Take the two glasses which are the same size. Fill them each with different amounts of water. One container should have significantly more liquid. Let’s call this one A. The one with less liquid will be B. 3. Consider what will happen if we pour water from A to B. Describe the overall change which will happen to B when this happens. Think about the situation in terms of equilibrium. Pour the water as described in