CHEM.9.C

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The student is expected to perform stoichiometric calculations, including determination of mass relationships, gas volume relationships, and percent yield; and
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Knowledge and Skills Statement

Science concepts. The student understands how matter is accounted for in chemical reaction.

As an educator, it is important to remember that stoichiometry calculations assume that all of the following conditions are met:
1. all of the reagent is consumed;
2. there is no deficiency of the reagent;
3. there is no excess of the reagent; and
4. the reaction proceeds to completion.

a chemical change that occurs when two or more substances combine to form a new substance; the rearrangement of atoms to produce new compounds

material substance that occupies space, has mass, and is composed predominantly of microscopic particles

relating to or denoting quantities of reactants or products in simple integer ratios as prescribed by a balanced chemical equation or formula

Research

Jammeh, Abdou L. J., Claude Karegeya, and Savita Ladage. "Misconceptions On Basic Stoichiometry Among The Selected Eleventh-Grade Students In The Urban Regions Of The Gambia." Journal of Baltic Science Education 22, no. 2 (2023): 254-268. https://files.eric.ed.gov/fulltext/EJ1386928.pdf

Summary:  The study complements previous research on a case study of chemistry lesson plan design and teaching. The present study developed a survey research method to assess students' misconceptions about basic stoichiometry. The study concluded that chemistry education can indicate the success of introducing basic stoichiometry, including referencing to the lower grades, rather than secondary grades.

Research

Wagner, Eugene P. "A Study Comparing the Efficacy of a Mole Ratio Flow Chart to Dimensional Analysis for Teaching Reaction Stoichiometry." School Science and Mathematics 101, no. 1 (2001) 10-22. doi:10.1111/j.1949-8594.2001.tb18185.x.

Summary:  Dimensional analysis is one of the main ways students are taught to solve [reaction stoichiometry calculations]. However, this methodology does not provide all students with a complete understanding of how to solve these problems. Introduction of alternative problem solving techniques, such as proportional reasoning, can help to improve student understanding. The mole ratio flow chart (MRFC) is a logistical sequence of steps that incorporates molar proportions.