Reflection: Problem-based Approaches Evaluating Reaction Rate Data using Stoichiometry - Section 1: Introduction

I love this lesson. When students did a trial run of their experiment in order to see how they might need to revise their noticed students making measurement errors. Because the reaction begins to happen right away, it is important to know the starting mass of the two reactants before combining them; they immediately start giving off CO2 when combined.

The correct procedure is to obtain the chemicals, mass them, add these two masses together, and then enter the total mass under the mass column at time 0 seconds. Various deviations from this procedure lead to measurement errors. For example, if you try to take the mass after combining the chemicals, and the reaction happens fast, you will not get an accurate total starting mass. Or, if you tare the balance before putting the beaker on it, or after you add one chemical, these mistakes would also lead to measurement errors.

The key question I have for students is, “How do you know if the data you generated is data that does not contain significant measurement errors?” The answer is stoichiometry. Once students know what their reaction is capable of producing, they can compare their actual yield to this theoretical yield. By doing this calculation, students become empowered to truly evaluate their data, rather than generating a number for which they do not have any context.

Giving Students a Tool to Self-assess
Problem-based Approaches: Giving Students a Tool to Self-assess

Evaluating Reaction Rate Data using Stoichiometry

Unit 6: Reaction Rates
Lesson 5 of 8

Big Idea: Performing stoichiometry is the only way to determine the theoretical yield from a chemical reaction.

Print Lesson
2 teachers like this lesson
Standards:
Subject(s):
60 minutes

Keith Wright

Similar Lessons

Chemical Reaction Equations--An Introduction
High School Chemistry » Chemical Reactions and Stoichiometry
Big Idea: Starting materials in scientific processes are called "reactants" and "products" are the result; reactants that run out limit the amount of product made, leftovers are called excess.
Favorites(14)
Resources(15)
Los Angeles, CA
Environment: Urban

Factors that Affect Solution Formation
High School Chemistry » Unit 8: Water Quality
Big Idea: Temperature, stirring, surface area, and pressure affect the solubility of a solute in a solvent when forming a solution.
Favorites(8)
Resources(27)
Chula Vista, CA
Environment: Urban

Exploring Collision Theory
High School Chemistry » Kinetics and Equilibrium
Big Idea: For chemical reactions to occur, particles must collide with precise alignment and enough kinetic energy.
Favorites(4)
Resources(12)
Blue Island, IL
Environment: Urban