<![CDATA[This research aims to describe the practicality and effectiveness of problem solving model in improving students' communication skills and mastering the concept of students’ acid-base. The sampling was done by purposive sampling technique, obtained class XI IPA 2 as an experimental class and XI IPA 3 as a control class. This study uses a quasi-experimental method with a pretest-posttest control group design. Practicality is measured based on the implementation of the lesson plan and students’ responses to the implementation of learning. Effectiveness is measured through communication skills and the difference in the average value of n-Gain mastery of students' concepts. The result showed that the problem solving model is practical and effective in improving communication skills and mastering the concept of students' acid-base.Keywords: problem solving model, communication skills, concept mastery, acid-base Penelitian ini bertujuan untuk mendeskripsikan kepraktisan dan keefektivan model problem solving dalam meningkatkan keterampilan komunikasi dan penguasaan konsep asam basa siswa. Pengambilan sampel dilakukan dengan teknik purposive sampling, didapatkan kelas XI IPA 2 sebagai kelas eksperimen dan XI IPA 3 sebagai kelas kontrol. Penelitian ini menggunakan metode kuasi eksperimen dengan pretest-postest control grup design. Kepraktisan diukur berdasarkan keterlaksanaan RPP dan respon siswa terhadap pelaksanaan pembelajaran. Keefektivan diukur melalui keterampilan komunikasi dan perbedaan rata-rata nilai n-Gain penguasaan konsep siswa. Hasil penelitian menunjukkan bahwa model problem solving praktis dan efektif dalam meningkatkan keterampilan komunikasi dan penguasaan konsep asam basa siswa.Kata Kunci: model problem solving, keterampilan komunikasi, penguasaan konsep, asam basa]]>
