Kinetics Discovery Lab
Today and tomorrow we are going to examine different aspects of kinetics. As small teams, and as a full class, we are going to explore and analyze the factors that affect reaction rate.
Lesson Objectives
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Learning Objective
4.1 The student is able to design and/or interpret the results of an experiment regarding the factors that may influence a reaction rate. Objectives and Practices as stated by The College Board |
Science Practices
1.4 The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively. 4.2 The student can design a plan for collecting data to answer a particular scientific question. 5.1 The student can analyze data to identify patterns or relationships. 6.1 The student can justify claims with evidence. |
Background
The Devils Chimney on Leckhampton Hill, near Cheltenham, Gloucestershire, England.
Public Domain
Calcium carbonate, CaCO3, is one of the most abundant minerals on the Earth. More than 4% of the Earth’s crust is composed of calcium carbonate. It is a major component in limestone, marble, seashells, bedrock, etc. Limestone and marble have been among the most widely used building materials for more than 5000 years, from the pyramids in Egypt to the Parthenon in Greece and the Taj Mahal in India.
In many places, limestone is also the foundation of our Earth—literally, since it is forms both bedrock and mountain ranges. Calcium carbonate dissolves in water to only a limited extent, but its solubility is greatly enhanced when the water is acidic. The gradual dissolution of marble and limestone, as well as coral and seashells, in acids is due to acid−base neutralization. The products of the neutralization reaction between calcium carbonate and hydrochloric acid are calcium chloride and carbonic acid, or H2CO3. Carbonic acid is unstable, decomposing to give carbon dioxide gas and water.
In many places, limestone is also the foundation of our Earth—literally, since it is forms both bedrock and mountain ranges. Calcium carbonate dissolves in water to only a limited extent, but its solubility is greatly enhanced when the water is acidic. The gradual dissolution of marble and limestone, as well as coral and seashells, in acids is due to acid−base neutralization. The products of the neutralization reaction between calcium carbonate and hydrochloric acid are calcium chloride and carbonic acid, or H2CO3. Carbonic acid is unstable, decomposing to give carbon dioxide gas and water.
The rate of the overall reaction (see below) and its dependence on the concentration of HCl are important concerns in environmental chemistry due to the combined effects of acid rain and ocean acidification.
This is the apparatus you will use to collect the gas. A plastic syringe with a stopcock assembly and adapter is fitted to a single-hole rubber stopper. The rubber stopper should fit snugly into the mouth of an Erlenmeyer flask, which is braced with a ring stand and clamp.
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The purpose of this advanced inquiry lab is to design kinetics experiments for the heterogeneous reaction of calcium carbonate with hydrochloric acid. The investigation begins with an introductory activity to observe the evolution of carbon dioxide gas from the decomposition of calcium carbonate with acid. Special equipment is provided to collect and measure the volume of gas generated (see picture at left). Using a cooperative approach, different groups will compare data for mass loss and volume of gas generation versus time. Initial rates and the rate law for the reaction are determined by graphical analysis of the results. The effects of temperature and particle size or surface area on the reaction rate provide additional opportunities for inquiry.
All italicized text taken from the Flinn Scientific Lab: Rate of Decomposition of Calcium Carbonate
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The Mission
Your task is to determine the effect of various factors on the rate of the calcium carbonate-hydrochloric acid reaction. This will be accomplished by measuring the carbon dioxide gas produced. You will then analyze the effects and explain, using your data as evidence, how different factors affect reaction rate.
Day 1The class will read the background information and be assigned to their partners. Ms. Cool will demonstrate the gas apparatus with calcium carbonate chips and 6M hydrochloric acid. This will be considered the control. Data will not be collected at this time, it is merely for demonstration purposes.
The class will then discuss the factors that affect the rate of a chemical reaction. Using the equipment and parameters outlined below, you will work in a shared document to design 1 control experiment and 4 different tests. Due to time pressures, only one trial will be conducted, however, "good science" means your results must be able to be replicated. Scientists never draw conclusions after one trial, however most scientists are also not facing the countdown of days to the AP Chemistry Exam this May! Experimental Design shared document |
Chemicals Available
Equipment Available
Restrictions
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Day 2
Based on the information determined the day before, Ms. Cool will have the lab materials ready as necessary.
As a class, we will conduct the 5 experiments, preferably simultaneously, and record the data in a common spreadsheet.
Data will be analyzed, graphs will be made, and conclusions will be drawn (oh my!). Ultimately, each person will write an analysis and conclusions summarizing their information, drawing conclusions about their data, and supporting it with evidence.
As a class, we will conduct the 5 experiments, preferably simultaneously, and record the data in a common spreadsheet.
Data will be analyzed, graphs will be made, and conclusions will be drawn (oh my!). Ultimately, each person will write an analysis and conclusions summarizing their information, drawing conclusions about their data, and supporting it with evidence.
Day 2 and Beyond - Independent Analysis & Conclusions
You will receive from me a document (<-- this is a sample) with this information to complete your final analysis and conclusions. You will use information from the previous 2 documents to help analyze your information.
Standards Info for Teachers
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Other Standards
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Reading
ELA.RST.11-12.4; ELA.RST.11-12.7 Writing ELA.W.11-12.1; ELA.W.11-12.4; ELA.W.11-12.5; ELA.W.11-12.6; ELA.W.11-12.7 Speaking and Listening ELA.SL.11-12.1; ELA.SL.11-12.2; ELA.SL.11-12.4;ELA.SL.11-12.5 Langauge ELA.L.11-12.1 ; ELA.L.11-12.2; ELA.L.11-12.4 |
Math Practices
HS MP 1, 2, 3, 4, 5, 6 Science & Engineering Practices HS SEN 1, 2, 3, 4, 5, 6, 7 Next Generation Science Standards HS-PS1-5 ISTE/NETS Standards for Students Creativity & Innovation - 1A, 1C, 1D Communication & Collaboration - 2A, 2B, 2D Research & Information Fluency - 3A, 3D Critical Thinking, Problem Solving, etc. - 4B, 4C Digital Citizenship - 5A, 5B, 5C, 5D Technology Operation - 6A |