The Qualities of Tasks in General Chemistry Based on the Analysis of Entrance Procedure at the Faculty of Science, Charles University
Abstract
This article introduces results of item analysis of chemistry tests used as a part ofthe admission procedure at the Faculty of Science, Charles University, between 2016and 2019. The aim of the analysis focusing on general chemistry was to determinewhich tasks were the most troublesome for applicants and those with a low discrimi-nation index.
The troublesome tasks were found based on the calculation of difficultindexes whereas the item discrimination index was represented by ULI(1/2) and RIRcoefficients. The results of the item analysis showed that ideal gas law is the hardestand only troublesome topic.
Moreover, there were four topics including at least onetroublesome item (pH calculation, electron configuration, ion product calculation,and chemical equilibrium).Additionally,theanalysis revealed threetopics containingan item with a low discrimination index (thermal decomposition, rate law, chemicalequilibrium)and,in manycases, itsvaluedecreased with anumberofstepsnecessaryfor reaching the solution in the task.