Answer:
Determining the pH of substances such as purple grape juice and catsup using test strips can be difficult. Why?
Explanation:
Due to the tartaric acid present in these substances, this is a weak acid and is the predominant type of acid in grapes.
pH meters for these substances, measure the total acidity of the sample and convert it into tartaric acid concentration; The test strips are a qualitative method of measurement and their result can give different opinions.
Tree sap is a viscoelastic polymer, which means it's not really a solid but a very viscous (sticky) fluid. It's fluidity ensures that it can properly <span>seal the spaces between the planks on wooden boats. Not only that, the pitch sap is hydrophobic - it is water resistant as well. </span>