The graph shows the changes in pH during a titration - HSC - SSCE Chemistry - Question 14 - 2015 - Paper 1
Question 14
The graph shows the changes in pH during a titration.
Which pH range should an indicator have to be used in this titration?
(A) 3.1–4.4
(B) 5.0–8.0
(C) 6.0–7.6
(D)... show full transcript
Worked Solution & Example Answer:The graph shows the changes in pH during a titration - HSC - SSCE Chemistry - Question 14 - 2015 - Paper 1
Step 1
Identify the pH range from the graph
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Answer
Examine the graph to determine where the steep change in pH occurs. The graph shows a significant increase from around pH 4 to pH 10. The inflection point indicates that the equivalence point of the titration is around pH 8.
Step 2
Determine the suitable indicator range
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Answer
Based on the equivalence point at pH 8, the appropriate indicator should transition near this point. Therefore, an indicator that changes color in the range of approximately 8.3 to 10.0 would be suitable.
Step 3
Select the correct answer option
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Answer
Thus, the correct choice for the pH range that the indicator should function in is (D) 8.3–10.0.
