Indicator Color Changes in Acid-Base Titration

Steps:

• Identify methyl orange color change: red in acid to yellow in base, matching statement 1.
• Check thymol blue color change: blue in base to yellow in acid, not blue to colorless, so statement 2 is false.
• Note same endpoint volume (23.6 cm³) for both indicators implies equivalent titration, but thymol blue's weaker color requires lower concentration for clear observation, confirming statement 3.
• Evaluate options: only 1 and 3 hold, selecting C.

Why C is correct:

• C includes statements 1 and 3, aligning with standard indicator pH transitions where methyl orange shifts red-to-yellow at pH 3.1-4.4, and thymol blue's dilute solution (typically 0.04% vs. methyl orange's 0.1%) ensures visibility without interference.

Why the others are wrong:

• A includes 2, but thymol blue does not turn colorless.
• B includes 2, incorrect for thymol blue's actual blue-to-yellow shift.
• D excludes 1, but methyl orange's red-to-yellow is standard.

Final answer: C