Question

kar 10-1 12. What sort of titration is the adjacent titration curve? Circle the correct response and explain your choice. SA/SB, SA/WB, SB/WA pH 13. Where is the effective buffer region in this titration curve? Circle this region on the graph. 4) Estimate the Ks of the weak base being titrated in this curve. . 10 20 30 13) Why does the pink color of phenolphthalein fade away? Was the equivalence point for the SA/SB system really where you expected it to be, at pH 7 (look at the pH corresponding to the middle part of the near vertical section)? If it wasn't both of these are caused by the same phenomenon. What do you think it is? Hint: Is soda pop acidic? Why?

Answer 1

# 12 . The given titration curve have initial pH value approximately equals to ll (which indicates weale base), if it were strong base then initial pH would be about 13. The pH value after equivalence point is about 2 ,which indicates strong acid, if it were weak aid pH after equivalence point would be about 4.5. Thus given curve is of weak base (WB) y's strong acid (sa). option (2) SA/WB) is the correct answer.