Universal indicator test on a lemon. A piece of universal indicator paper held against the flesh of a freshly cut lemon. The change of colour from yellow to red shows that the lemon is very strongly acidic. Lemons,like all citrus fruits,contain citric acid. Universal indicator paper changes its colour depending on the pH of the solution tested. It is used to measure the strength of an acid or an alkali. pH is a logarithmic measure of hydrogen ion concentration. Acid solutions have a high concentration of hydrogen ions,while alkali solutions have a low concentration of hydrogen ions | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Science Source |
Taille de l’image : | 4704 px × 2742 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : |
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