Which indicator is commonly used for a strong acid-strong base titration?
Practice Questions
Q1
Which indicator is commonly used for a strong acid-strong base titration?
Phenolphthalein
Methyl orange
Bromothymol blue
Litmus
Questions & Step-by-Step Solutions
Which indicator is commonly used for a strong acid-strong base titration?
Correct Answer: Phenolphthalein
Step 1: Understand what a titration is. It is a method used to determine the concentration of a solution by adding a solution of known concentration.
Step 2: Identify the types of solutions involved. In a strong acid-strong base titration, one solution is a strong acid (like hydrochloric acid) and the other is a strong base (like sodium hydroxide).
Step 3: Learn about indicators. Indicators are substances that change color at a certain pH level, helping to show when the reaction is complete.
Step 4: Know the pH range for strong acid-strong base titrations. The pH at the equivalence point (where the acid and base completely react) is around 7.
Step 5: Find out which indicator is suitable. Phenolphthalein is commonly used because it changes color in the pH range of 8.2 to 10, which is slightly above neutral.
Step 6: Conclude that phenolphthalein is a good choice for indicating the endpoint of a strong acid-strong base titration.
