EVALUATION OF HIBISCUS AND ROSE FLOWER EXTRACTS AS ECO FRIENDLY NATURAL PH INDICATORS FOR ACID–BASE TITRIMETRIC ANALYSIS . Pimrj [Internet]. 2026 May 11 [cited 2026 May 12];4(2):112-5. Available from: https://pimrj.org/index.php/pimrj/article/view/347