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Indicators are usually very weak acids, which establish an equilibrium in solution. So, if HA is the indicator,
HA <---> H+ + A-
where A- and HA have different colors. [Note that the equation is reversible (<--->)]
When the indicator is in acidic conditions, the equilibrium shifts to the left (<<--) because there are excess H+ (Le Chatalier's Principle). This means that more of HA are formed, showing the color of HA. Likewise, when the indicator in basic conditions, the equilibrium shifts to the right (-->>) because there are few H+ ions in the solution(reacted with the OH- ions of the base). This means that more A- will be formed, showing the color of A- .
You can now see that in acidic solutions, you will see the color of HA, while in basic conditions, you will see the color of A- .
Wiki User
∙ 13y ago
Indicators are substances that change color in response to changes in pH. In acidic conditions, indicators such as litmus turn red, while in basic conditions they turn blue. This color change is due to the differing chemical structures of the indicator molecules in the presence of different hydrogen ion concentrations.
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Why is it that the presence of indicator does not affect reaction between acid and base?
Indicators do not interfere with the reaction between an acid and a base because they are typically weak acids or bases themselves. They only change color depending on the pH of the solution but do not participate in the acid-base reaction. This allows the reaction between the acid and base to proceed as normal.
Are indicators acidic or basic in nature?
Indicators can be both acidic and basic in nature, depending on their color change properties in response to different pH levels. Some indicators change color in acidic solutions, while others change color in basic solutions.
What is a compound that changes color when in contact with an acid or a base called?
That compound is called an acid-base indicator. These indicators change color based on the pH of the solution they are in, making them useful for identifying whether a substance is acidic or basic.
What is recreation of indicator with acid and base?
Recreation of an indicator using an acid and a base involves mixing a colorless or faintly colored acid-base indicator with an acid to make the solution acidic (and change color) and then adding a base to neutralize the acid and return the indicator to its original color. This process demonstrates the reversible nature of acid-base indicators and how they can be used to visually indicate the presence of acids or bases in a solution.
Why methyl orange used in the titration and not other indicator?
Methyl orange is commonly used in acid-base titrations because it changes color sharply in the pH range of about 3.1 to 4.4, making it easy to detect the endpoint. Other indicators may have different color change ranges that may not be ideal for acid-base titrations.
What are acid-base indicators?
Acid-base indicators, are chemicals that change color in response to acidic or basic conditions.
What is acid-base indicators?
These indicators change the color depending on the pH of the solution.
what acid-base change color when in contact with an acid or a base?
pH indicators change the color in contact with acids or bases.
What is reacts to indicators a base neutral or acid?
An indicator has a different color in acidic or basic solutions; the nature of complexes formed is different.
What are acid base indicators?
These indicators are substances which change their color depending upon acidity/basicity of the solution.
What will change color in the presence of an acid or a base?
pH indicators change the color depending upon acidity or basicity.
What are some indicators?
Indicators are chemicals that change color in the presence of an acid or a base. The most commonly used indicator is phenophthalein.
What changes color in the presence of and acid or a base?
Various "indicators". Perhaps the most common is litmus.
Why is it that the presence of indicator does not affect reaction between acid and base?
Indicators do not interfere with the reaction between an acid and a base because they are typically weak acids or bases themselves. They only change color depending on the pH of the solution but do not participate in the acid-base reaction. This allows the reaction between the acid and base to proceed as normal.
What is used to determine the presence of acids and bases by a change in color?
Acid-base indicators are used for this purpose.
Are indicators acidic or basic in nature?
Indicators can be both acidic and basic in nature, depending on their color change properties in response to different pH levels. Some indicators change color in acidic solutions, while others change color in basic solutions.
What kinds of compounds are called acid base indicators?
Acid-base indicators are usually weak organic acids or bases that change color in response to changes in pH. They are commonly used in titrations to help determine the endpoint of the reaction based on color changes. Examples include phenolphthalein, litmus, and methyl orange.
