Which of the following is true about indicators?
A. They are weak acids or bases.
B. They are as accurate as a pH meter.
C. They maintain their colors across the range of pH values for which they are used.
D. all of the above
is it A???
Yes, A is correct. C is worded funny and I don't know what it means but it could be true depending upon how it is interpreted.
To determine the correct answer, let's analyze each option:
A. They are weak acids or bases: This statement is true. Indicators are chemical compounds that can be weak acids or weak bases. They have the ability to change color in response to changes in pH.
B. They are as accurate as a pH meter: This statement is not necessarily true. While indicators can provide a rough estimate of the pH, they are not as accurate as a pH meter. pH meters use electrodes to directly measure the hydrogen ion concentration in a solution.
C. They maintain their colors across the range of pH values for which they are used: This statement is not always true. Indicators have specific pH ranges where they exhibit distinct colors. However, outside of these ranges, their colors may not be as reliable.
Therefore, the correct answer is not A. Now, let's assess the remaining options:
B. They are as accurate as a pH meter: We have established that this statement is not true.
C. They maintain their colors across the range of pH values for which they are used: We have also established that this statement is not always true.
Since none of the statements are entirely accurate, the correct answer is not D (all of the above).
In conclusion, the correct answer is none of the options provided.