Abstrak. Telah dilaksanakan penelitian quasi experiment dengan “pre-test post-test non-equivalent control group design”. Sampel penelitian kelas XI MIPA 2 dan 3 SMAN 6 Banjarmasin dengan teknik cluster random sampling. Variabel bebasnya model PBL dengan pendekatan multilevel representasi dan model PBL. Variabel terikatnya penguasaan konsep. Data dianalisis secara deskriptif dan inferensial. Hasil dari penelitian didapatkan perbedaan signifikan pada implementasi model PBL dengan pendekatan multilevel representasi serta model PBL diperoleh t_hitung  > t_tabel (4,10 > 2). Implementasi model PBL dengan pendekatan multilevel representasi mendapatkan respon yang sangat baik.

Kata kunci: Model PBL, pendekatan multilevel representasi, penguasaan konsep, kesetimbangan ion dalam larutan garam.

Abstract. Quasi experiment has been implemented with “pre-test post-test non-equivalent control group design”. The sample of this research are class XI MIPA 2 and 3 SMAN 6 Banjarmasin with cluster random sampling technique. Independent variable are PBL model and multilevel representation oncoming and PBL model. Dependent variable is mastery of concepts. Data were analyzed descriptive and inferential. The results of this research found a significant difference in implementation of PBL model and multilevel representation oncoming and PBL modelwere obtained t_count > t_table (4,10 > 2). Implementation of PBL model and multilevel representation oncoming get a very good response.

Keywords:  PBL model, multilevel representation oncoming, mastery of concepts,                              equilibrium ion in a salt solution.