The PH of a solution can be measured using the H+ ions concentration present in the solution. PH= -log(H+) H+ is the hydrogen ion concentration. or by knowing the OH- ion concentration. PH= 14- (-log(OH-)-log(OH-) is the pOH of the solution.
An avocadoâs exterior can tell a lot about whatâs happening inside. If you pay attention to the clues its color, texture, and firmness provide, you will select a perfectly ripe avocado each time. Below I describe four methods you can use to tell if an avocado is ripe. A. Skin color. An avocado with a darker skin is often riper than one with a lighter skin. 1  Scan the avocados in front of you.  The avocados with darker green-to-black skin colors may be riper than those with with lighter skins.
On the other hand, green oranges are likely immature, although some varieties, like satsumas, can be ripe yet still show a little green. But while most ripe oranges will be a deep rich color, not all fruit that is a deep, ripe color will be ripe.