1) oi50 . tinypic . com / ejh6vm . jpg
The most suitable indicator for the titration is:
A)methyl violet
B)chlorophenol red
C)methyl orange
D)phenolphthalein
2-A base is titrated with an acid solution until the indicator changes colour. This change in the colour of the indicator is referred to as the
A)end point
B)neutralization point
C)equilibrium point
D)equivalence point
1) In order to determine the most suitable indicator for the titration, we need to examine the given image or provide a description of the substances involved in the titration. Without this information, it is not possible to determine the most suitable indicator from the options given (methyl violet, chlorophenol red, methyl orange, phenolphthalein).
2) The change in the color of the indicator during a titration is referred to as the "end point." The end point is the point at which the reaction between the acid and base is considered complete. It is important to note that the end point may not always coincide with the true equivalence point, which refers to the stoichiometrically equal amounts of the acid and base being reacted.
To find the most suitable indicator for a titration, you need to consider the pH range at which the indicator changes color and the pH range at which the equivalence point (the point at which the acid and base have reacted completely) occurs.
1) Looking at the given options for the indicator, let's consider their pH ranges:
- Methyl violet: pH range of 0.0 to 1.6 (red to violet color change)
- Chlorophenol red: pH range of 4.2 to 6.8 (yellow to red color change)
- Methyl orange: pH range of 3.1 to 4.4 (orange to pink color change)
- Phenolphthalein: pH range of 8.2 to 10.0 (colorless to pink color change)
To determine the most suitable indicator, we need to know the pH range at which the equivalence point occurs in the acid-base titration being performed. Without that information, we can make an educated guess by considering the pH values commonly encountered in acid-base titrations:
- The equivalence point for strong acid-strong base titrations usually occurs around a pH of 7.
- The equivalence point for weak acid-strong base titrations usually occurs above pH 7, closer to the pH of the weak acid's conjugate base.
- The equivalence point for strong acid-weak base titrations usually occurs below pH 7, closer to the pH of the weak base's conjugate acid.
Looking at the given options, methyl orange and phenolphthalein seem to cover a wider range of pH values that are typically encountered in acid-base titrations. Since we don't have the specific details about the titration being performed, we can't give a definitive answer. However, methyl orange (option C) and phenolphthalein (option D) are likely to be more suitable indicators based on their pH ranges.
2) The change in color of the indicator during a titration is referred to as the "end point" (option A). It indicates that the acid and base have reached a point where they have reacted in the stoichiometric ratio. When the indicator changes color, it marks the approximate position of the equivalence point (option D), which is the exact point at which the acid and base have reacted completely. However, it's important to note that the end point and equivalence point are not always the same.