本研究探究高三學生酸鹼鹽的迷思概念。參與研究的學生為南部兩所公立高中及北部一所公立高中的高三學生共335名,研究工具為研究者自行設計含24題多項式選擇題之測驗,此測驗經過三位高中教師審查,信度為α=.75。所得資料求其描述性統計及皮爾遜積差相關。研究發現最重要的迷思概念有:1)學生直接由Ka取對數決定弱酸溶液的pH值;2)不瞭解解離度和Ka值之關係;3)對於兩弱酸混合時沒有競爭反應的概念:4)不清楚Na2CO3的酸鹼性的判斷。本研究建議在教學方面加強:1)Ka值的計算;2) 競爭反應的概念;3) 緩衝溶液。在研究方面建議進一步探討:1)Na2CO3 水溶液的水解;2)在酸鹼中和時,對於不同的溶液,使用相同的滴定液,學生為何會認為滴定達到當量點時,各溶液酸鹼性相等。
Investigated were the misconceptions of acid-base-salt of the 12th grades’ students. Three hundreds and thirty-five students who had studied acid-base-salt participated in the study. Twenty-four multiple-choose test was developed by the researcher. The test was validated by three high school teachers , the reliability (α) of the test is 0.75. Data was analyzed through descriptive statistics and Pearson product-moment correlations . Major findings are : 1)students judged the pH value of weak acid solutions by using Ka value directly; 2)students didn’t understand the relationship about Ka and strength of acid; 3)when two weak acids were mixed together students counted the concentration of hydrogen ion of the solution without the concept of competition in the reaction;4)students were confused with the solution of Na2CO3 about how they hydrolysis with water, and how come they will be acidic or basic. The study recommended more emphasis on teaching the calculation of Ka , concept of competition and buffer solutions . Further studies related to hydrolylsis of Na2CO3 and the reasons why students thought using same titer in different solutions result in the same pH while neutralization are suggested.