The Misconception of Stoichiometry and Its Impact on the Chemical Equilibrium

Abstract

Misconception about stoichiometry and its impact on the chemical equilibrium concept were studied on 245 second-grade students at SMA Negeri 2 Gowa, South Sulawesi, Indonesia. Research instruments were Stoichiometry misconception test (SMT) and chemical equilibrium misconception three tier tests (CEMTT). Semi structured interview was conducted after the administration of the test for fifteen students. SMT consisted of ten items with high validity of 90.70% and reliability coefficient, calculated using Cronbach's alpha, of 0.73 (high). CEMTT consisted of thirdteen items with very high validity of 96.70% and reliability coefficient, calculated using Cronbach's alpha, of 0.95 (very high). The effect of stoichiometry misconceptions on chemical equilibrium was sufficient with limited predictions (r = 0.36). We identified three misconceptions stoichiometry that had impact on the misconceptions of chemical equilibrium concept namely: 1) The number of moles of substances that react is proportional to the number of atoms, relates to the increasing pressure will shift the equilibrium of the gas toward a substance that has more number of atoms; 2) The increasing of concentration will greather surface area, so as to giving rises to a greather number of effective collisions. This is related to the misconception that changes in the amount of solid phase at heterogeneous equilibrium which would shift the equilibrium system; 3) In exothermic reaction there is an increase in reaction enthalpy, relates to the misconception that the increase of temperature in exothermic gas equilibrium will shift towards the product. It was proven that there was a misconception relationship between the stoichiometry and chemical equilibrium, so it is recommended to implement a learning strategy that can prevent students' misconceptions on the concept of chemical equilibrium by eliminating students' misconceptions on the stoichiometry in chemistry learning.

The Effectiveness of The Six Tier Diagnostic Test (STDT) Instrument in Viewed from Empirical Validity to Identify Student's Misconceptions in Chemical Equilibrium Materials

“…Usu (2019), Siswaningsih (2019), andHarza (2021) argued that students often experience misconceptions about chemical equilibrium, especially in the dynamic equilibrium subtopic. Siswaningsih (2017), Jusniar (2019), Yamtinah (2019), Khairunnisa & Prodjosantoso (2020), Andriani, et al, (2020), and Jusniar (2020 suggested that apart from dynamic equilibrium, misconceptions about chemical equilibrium also occur in the sub-topics of equilibrium shifts and equilibrium constants. The research results regarding misconceptions about other chemical equilibriums developed by Omilani and Elebute (2020) suggest that misconceptions about chemical equilibrium material also occur in the sub-topic of factors that influence shifts in equilibrium.…”

The Effectiveness of Remediation Learning Strategy in Reducing Misconceptions on Chemistry: A Systematic Review

“…It can hinder understanding the next concept that is built on it. The following research by Jusniar et al, (2019) stated that misconceptions in stoichiometry (prerequisite concepts) could cause students to have difficulty understanding the material of chemical equilibrium and subsequently lead to misconceptions.…”

Effectiveness of Structured-Worksheet Use to Reduce Student Misconceptions in Stoichiometry

“…Rohmah chemistry that requires understanding qualitative and quantitative aspects related to chemical phenomena to solve various chemical problems in high schools and colleges (Sunyono, 2015). Stoichiometry is a chemical calculation that must be understood correctly because it underlies other chemical concepts, namely moles, chemical equilibrium (Jusniar et al, 2019) Based on the results of interviews with several chemistry teachers and students, it is known that students have difficulty in understanding the material because many concepts are abstract and mathematical calculations that make students confused. Misconceptions perhaps highly resistant to change, fixed for years, and unaffected by classroom teaching (Luoga et al, 2013).…”

“…Such difficulties can cause students to encounter misconception in stoichiometry (Nilawati, 2016) A misconception is a mismatch of students' understanding of science agreed upon by scientists (Barke et al, 2009;Mondal, B. et al, 2013). Misconception can be caused by teacher explanations, textbooks, and students' prior knowledge (Jusniar et al, 2019;Kelly et al, 2019).…”