wht is an acid base indicater? Give an example?
Answers
Answer:
In chemistry and cooking, many substances dissolve in water to make it either acidic or basic/alkaline. A basic solution has a pH greater than 7, while an acidic solution has a pH of less than 7. Aqueous solutions with a pH of 7 are considered to be neutral.1 Acid-base indicators are substances used to determine roughly where a solution falls on the pH scale.
Explanation:
Acid-Base Indicator Definition
An acid-base indicator is either a weak acid or weak base that exhibits a color change as the concentration of hydrogen (H+) or hydroxide (OH-) ions changes in an aqueous solution. Acid-base indicators are most often used in a titration to identify the endpoint of an acid-base reaction. They are also used to gauge pH values and for interesting color-change science demonstrations.
Also Known As: pH indicator
Acid-Base Indicator Examples
Perhaps the best-known pH indicator is litmus. Thymol Blue, Phenol Red, and Methyl Orange are all common acid-base indicators. Red cabbage can also be used as an acid-base indicator.
How an Acid-Base Indicator Works
If the indicator is a weak acid, the acid and its conjugate base are different colors. If the indicator is a weak base, the base, and its conjugate acid display different colors.
For a weak acid indicator with the genera formula HIn, equilibrium is reached in the solution according to the chemical equation:
HIn(aq) + H2O(l) ↔ In-(aq) + H3O+(aq)
HIn(aq) is the acid, which is a different color from the base In-(aq). When the pH is low, the concentration of the hydronium ion H3O+ is high and equilibrium is toward the left, producing the color A. At high pH, the concentration of H3O+ is low, so equilibrium tends toward the right side of the equation and color B is displayed.
Answer:
acid turn blue litmus to red and base turn red litmus to blue.example of acid-base indicators are litmus paper, phenolphthalein, and red cabbage juice.