A student carries out an acid-base titration to find the concentration of an aqueous ammonia solution (NH3\text{NH}_3NH3, a weak base) using hydrochloric acid (HCl\text{HCl}HCl, a strong acid).
The titration curve for this reaction is shown below:
Based on the titration curve, which of the following indicators is the most suitable for detecting the equivalence point of this titration?
Thymol blue (pH\text{pH}pH range 1.2−2.81.2 - 2.81.2−2.8)
Methyl red (pH\text{pH}pH range 4.4−6.24.4 - 6.24.4−6.2)
Phenol red (pH\text{pH}pH range 6.8−8.46.8 - 8.46.8−8.4)
Phenolphthalein (pH\text{pH}pH range 8.3−10.08.3 - 10.08.3−10.0)
Acids Questions
Practise Edexcel GCSE Chemistry Acids with exam-style questions for Foundation and Higher tier. 100 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.