Litmus paper test. Blue litmus paper turns red in the presence of an acid. The juice from the lemon contains citric acid. Litmus is an organic material derived from plants. Litmus paper is a quick test to show if a liquid is acid or alkali,but it does not show its strength | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Andrew Lambert Photography |
Taille de l’image : | 4307 px × 3267 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |