indicator paper, test paper, accutint test paper, reaction paper, reagent paper, lithmus paper, lithmus, lacmus
piece of paper is used to test materials for acidity, turning red when acidic and blue when alkaline, pabeririba, mis on kasutusel materjalide testimiseks happesuse suhtes, muutudes happelise keskkonna korral punaseks ja siniseks, kui on aluseline keskkond