KETERAMPILAN BERPENDAPAT SISWA KELAS XI SMA IPIEM SURABAYA MELALUI MODEL PENGAJARAN LANGSUNG DAN METODE DISKUSI KELAS PADA MATERI POKOK ASAM BASA(THE STUDENTS’ GIVING OPINION SKILLS IN XI GRADE OF SMA IPIEM SURABAYA BASED ON DIRECT INSTRUCTION MODEL ANDCLASSROOM DISCUSSION METHOD IN ACID BASE) - KARTIKA SARI EKA PRATIWI, SUCI (UNESA Journal of Chemical Education, 2014)