¬¬PEMANFAATAN EKSTRAK BUAH Psidium Guajava SEBAGAI GREEN INHIBITOR UNTUK KOROSI BESI PADA LARUTAN ASAM SULFAT - Akbar, Said Ali (CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry); Vol 7 No 1 (2019): Volume 7, Nomor 1, 2019, 2019)
ABSTRA K: Efek inhibisi dari ekstrak buah Psidium Guajava (PG) pada korosi logam besi dipelajari dengan menggunakan metode penurunan berat. Laju korosi besi dalam media PG-H 2 SO 4 berkurang secara relatif terhadap media larutan H 2 SO 4 tanpa PG. Efisiensi inhibisi meningkat dengan semakin banyaknya konsentrasi ekstrak dan serta kenaikan suhu. Efisiensi inhibisi tertinggi tercatat 83,63% pada konsentrasi ekstrak 10 g/L pada 60 °C. Energi aktivasi (E a ) korosi besi dalam medium PG-H 2 SO 4 lebih rendah dari pada tanpa PG. Parameter termodinamika yang telah dihitung menunjukkan bahwa proses inhibisi korosi adalah endotermik dan spontan. Adsorpsi PG pada permukaan besi sesuai dengan model adsorpsi isoterm Langmuir.   Kata Kunci : asam sulfat , green inhibitor, isoterm langmuir, Psidium Guajava     ABSTRA CT: The inhibitory effect of Psidium Guajava (PG) fruit extract on iron metal corrosion was studied using the weight loss method. The corrosion rate of iron in the PG-H 2 SO 4 medium was reduced relative to the medium of H 2 SO 4 without PG. The inhibition efficiency increases with increasing concentration of extracts and increases in temperature. The highest inhibition efficiency was 83.63% at an extract concentration of 10 g/L at 60 °C. The activation energy (E a ) iron corrosion in the PG-H 2 SO 4 medium was lower than without PG. Thermodynamic parameters that have been calculated, indicating the corrosion inhibition processes are endothermic and spontaneous. The adsorption of PG on the iron surface was accordance with the Langmuir isotherm adsorption model.