Question 1
Identify the pH at which bromothymol blue changes colour. (Bromothymol blue: pKₐ = 7.1)
Worked answer
🔒 Start free to see full answer
Chemistry · Unit 3 · Chemical equilibrium systems · Chemical equilibrium
Identify that indicators change colour when pH = pKa.
Practise this objective
AI-marked practice questions tied to QCAA mark schemes for this exact LO. Free to start.
Start free practicePractice questions for this objective
Full questions, answers and worked solutions unlock when you start a free practice session.
Question 2
Identify the pH at which bromothymol blue undergoes its most noticeable colour change.
Worked answer
🔒 Start free to see full answer
Question 3
Methyl orange is a pH indicator with a $pK_a$ value of 3.4. At what pH will methyl orange display its colour change?
Worked answer
🔒 Start free to see full answer
More in Chemical equilibrium
← Previous
Identify that buffers are solutions that are conjugate in nature and resist a change in pH when a small amount of an acid or base is added. (Buffer calculations are not required.)
Next →
Identify that physical changes are usually reversible, whereas only some chemical rea ctions are reversible.