https://cameo.mfa.org/index.php?title=Congo_red_paper&feed=atom&action=history Congo red paper - Revision history 2024-03-29T07:15:04Z Revision history for this page on the wiki MediaWiki 1.35.3 https://cameo.mfa.org/index.php?title=Congo_red_paper&diff=22869&oldid=prev at 12:01, 24 July 2013 2013-07-24T12:01:13Z <p></p> <p><b>New page</b></p><div>== Description ==<br /> <br /> A acid-base indicating paper. Congo red paper is made by impregnating filter paper with a 0.1% aqueous solution of Congo red dye. Congo red is red above pH 5 and blue below pH 3. It is only sensitive to strong acids (mineral acids) and not weak acids (organic acids).<br /> <br /> == Synonyms and Related Terms ==<br /> <br /> Congo blue paper; Riegel's paper; Herzberg's paper<br /> <br /> [[Category:Materials database]]</div>