pH is a measure of hydrogen ion concentration, a measure of the acidity or alkalinity of a solution.
Litmus paper Phenolphthalein Bromothymol Blue Red Cabbage
Beets: A very basic solution (high pH) will change the color of beets or beet juice from red to purple. Blackberries: Blackberries, black currants, and black raspberries change from red in an acidic environment to blue or violet in a basic environment.
Methyl red is a pH indicator used to identify pH values between 4.4 and 6.2. At low pH (4.4 and lower) the indicator solution is red. At high pH (6.2 and above) the color is yellow. Between pH 4.4 and 6.2, the indicator solution is orange. Bromocresol green is a pH indicator used to identify pH values between 3.8 and 5.4. Below pH 3.8 the indicator solution is yellow. Above pH 5.4 the solution is blue. Between pH values of 3.8 and 5.4, the indicator solution is green.
A solution with a pH of 7 is classified as neutral. If the pH is lower than 7, the solution is acidic. When pH is higher than 7, the solution is basic.
Neutralization (chemistry), a chemical reaction in which an acid and a base react quantitatively with each other.
Neutral substances that are the most well known are: water, table salt, sugar solution and cooking oil.