Strategies Undergraduate Students Use to Solve a Volumetric Analysis Problem before and after Instruction

Abstract

This study investigated the strategies students in general chemistry and analytical chemistry courses used before and after instruction to solve a volumetric analysis problem in which the molar ratio was not 1:1. Questions like this have historically been very challenging for high school and undergraduate students. Student writing on open-response problems was analyzed to determine the problem-solving approach and identify errors made during the calculation. The two most prevalent strategies on pretests and post-tests were calculating mole amounts and using the equation M 1 V 1 = M 2 V 2. Performance was significantly lower for students using the M 1 V 1 = M 2 V 2 as they often assumed a 1:1 molar ratio. The M 1 V 1 = M 2 V 2 heuristic was very popular despite its exclusion from formal instructional resources such as the textbook or lecture, and teachers seeking to improve instruction in this area must account for students using an approach not introduced in the classroom.

Investigating the Use of an Artificial Intelligence Chatbot with General Chemistry Exam Questions

“…Explanations for the closed-response questions were analyzed using the problem-solving framework proposed by Taasoobshirazi and Glynn 57 which has been used to analyze student written responses for questions involving solution stoichiometry. 58 In this model, problem solving begins with problem conceptualization. Problem conceptualization can take place on different scales.…”

“…Titration questions in which the stoichiometric ratio is not 1:1 are challenging because students often ignore the coefficients in the balanced equation and use the heuristic 58 The explanation provided by ChatGPT for this question is excellent, as the chatbot first discusses the balanced equation, then uses solution information to calculate the mole amount (although careful inspection reveals it actually calculates millimoles, not moles), then applies the reaction stoichiometry, and finally converts from mole amounts to volume. This is the procedure most commonly found in general chemistry textbooks, 58 and the explanation uses language a student could understand and avoids the most common student error. The chatbot's response in Table 3 is very typical of worked examples found in general chemistry textbooks and the correct answer feedback that homework systems provide.…”

“…The example in Table shows a titration question provided to ChatGPT and the resulting response; formatting used within the system is shown. Titration questions in which the stoichiometric ratio is not 1:1 are challenging because students often ignore the coefficients in the balanced equation and use the heuristic M 1 V 1 = M 2 V 2 . The explanation provided by ChatGPT for this question is excellent, as the chatbot first discusses the balanced equation, then uses solution information to calculate the mole amount (although careful inspection reveals it actually calculates millimoles, not moles), then applies the reaction stoichiometry, and finally converts from mole amounts to volume.…”

Comparing the Performance of College Chemistry Students with ChatGPT for Calculations Involving Acids and Bases

“…The categories of response included problem conceptualization, problem strategy, student errors in these areas, and errors in reaching the final solution. The analysis of student work using this approach has been previously reported for question 1 and question 4. , …”

“…It is also noteworthy that the M 1 V 1 = M 2 V 2 strategy was not included in classroom instruction, yet students "find" using other sources and misapply this heuristic during the semester. 38 Chatbot performance on question 4 was of particular interest given the student use of two different problem strategies, one of which led to lower scores. Overall, the chatbot performance on question 4 was high for both the acid and the base version.…”