The pH of a certain acid having a concentration of 0.20 M was measured. The pH was 2.50. Was this a strong or a weak acid?
I answered it is a strong acid because strong acids have a lower pH.
I am just not too sure if there is anything missing in my answer.
Any help would be appreciated.
1 answer
Your answer may or may not be right. However, the reasoning is incorrect. You know that if a 0.20 M acid is a strong acid that it must ionize completely; therefore, the (H^+) will be 0.2M and the pH will be about 0.7. The pH isn't 0.7 so it must b a weak acid. Does that make sense? A pH of 2.5 is a lower H^+ than pH 0.7 and you would have a lower H^+ for a weak acid.