Sour Acids and Bitter Bases

• To distinguish whether a substance is an acid or a base with different indicators,

• Observing color changes when different reagents are used in acid and base substances,

• To be able to rank the substances according to the scale of acidity and alkalinity,

• It is aimed to observe that we obtain a neutral solution (homogeneous mixture) as a result of the acid-base reaction

7Cp.02 Understand that the acidity or alkalinity of a substance is a chemical property and is measured by pH

7Cp.03 Use indicators (including Universal Indicator and litmus) to distinguish between acidic, alkaline and neutral solutions

BOOK DEMO

Acids are materials that can release a proton and bases are materials that can accept a proton. This

tendency to release or accept a proton is measured based on the concentration of H and OH ions.

These characteristics can also be observed using additive substances called indicators which change

color based on the acidity / basicity of the environment. Cabbage juice is a natural indicator. In this

experiment, the change in color of cabbage juice when added to different substances is observed.

Furthermore, HCl and NaOH are used to conduct a titration and the change in acidity of the

environment is seen as change in the color of phenolphthalein indicator added to the solution.

Assessing Acid-Base Properties of Various Substances