The following diagram represents a buffer composed of equal concentrations of a weak acid, HA, and its conjugate base, A-. The heights of the columns are proportional to the concentrations of the components of the buffer. (a) Which of the three drawings, (1), (2), or (3), represents the buffer after the addition of a strong acid? [Section 17.2]

Video transcript

Welcome back everyone in this example the image shows below a buffer with equal amounts of weak acid H. A. And its conjugate base A minus. If the column heights pertained to the amount of the component present, select the image that shows the buffer after a strong acid is added. So we're going to recognize that right now we have equal concentrations of weak acid and conjugate conjugate base. Now if we were to add a strong acid we would expect our concentration of the conjugate base to decrease whereas our concentration of weak acid should remain the same. And the only image that corresponds to that change would be depiction three where if we add a strong acid, Our concentration of our weak acid should be unaffected but our concentration of conjugate base definitely does decrease from being at this level two. Now this level here and so image three would be the correct depiction as our final answer due to the fact that we recognize that with the addition of a strong acid to a buffer solution or to a buffer. Our conjugate base is converted too weak acid and so therefore we will have more weak acid then conjugate base which is why our concentration again of conjugate base decreases. So image three is our final answer corresponding to choice C. In the multiple choice. I hope everything I explained was clear. If you have any questions, let them down below and I will see everyone in the next practice video