Acid-base titration curves and indicators

36 questions on Acid-base titration curves and indicators from the Ionic Equilibrium II chapter: 7 NEET level, 14 JEE Main, 15 JEE Advanced. Each one opens with its answer and solution.

• Methyl orange (colour change range pH 3.1 to 4.4) is a suitable indicator for the titration of NEET level
• A weak acid HA (K_a = 1x10^-5) is half neutralised by NaOH. The pH of the solution is NEET level
• At the equivalence point of the titration of acetic acid with sodium hydroxide at 298 K, the pH is NEET level
• 25.0 mL of 0.100 M acetic acid (K_a = 1.8x10^-5) is titrated with 0.100 M NaOH. The pH after adding 10.0 mL of NaOH is JEE Main level
• 25.0 mL of 0.10 M HCl is mixed with 20.0 mL of 0.080 M NaOH. Use log 2 = 0.301. The pH of the mixture is closest to JEE Main level
• 25.0 mL of 0.10 M acetic acid is titrated with 0.10 M NaOH (K_a = 1.8x10^-5). Indicator ranges: methyl orange 3.1-4.4; methyl red 4.2-6.3; bromothymol blue 6.0-... JEE Main level
• 20.0 mL of 0.10 M formic acid (K_a = 1.8x10^-4) is titrated with 0.10 M NaOH. Calculate the pH at the equivalence point at 298 K, using pH = 7 + tfrac12(pK_a + ... JEE Main level
• 30.0 mL of a 0.10 M weak monoprotic acid HA (K_a = 2.0x10^-5) is titrated with 0.10 M NaOH. At what volume of NaOH added (in mL) will the pH be exactly pK_a + 0... JEE Main level
• A 0.10 M weak acid HA with pK_a = 5.0 is titrated with 0.10 M NaOH. Which statements are correct? (log 9 = 0.954.) JEE Main level
• A weak-acid indicator HIn has K_In = 1.0x10^-5. Assume the acid colour is seen when [HIn]/[In-] ge 10 and the base colour when [In-]/[HIn] ge 10. Select the cor... JEE Main level
• 20.0 mL of 0.10 M H2A (pK_a1 = 3.0, pK_a2 = 7.0) is titrated with 0.10 M NaOH. Use log 3 = 0.477 and treat each stage as a buffer. The pH after 25.0 mL of NaOH ... JEE Advanced level
• 25.0 mL of a mixture that is 0.10 M in HCl and 0.10 M in CH3COOH is titrated with 0.10 M NaOH (K_a = 1.8x10^-5 for acetic acid). At the first end point, where a... JEE Advanced level
• 40.0 mL of 0.10 M aqueous NH3 (K_b = 1.8x10^-5) is titrated with 0.10 M HCl. Using log 3 = 0.477, calculate the pH after adding 30.0 mL of HCl. Give two decimal... JEE Advanced level
• 50.00 mL of 0.100 M HCl is titrated with 0.100 M NaOH at 298 K (K_w = 1.0x10^-14). Calculate the change in pH produced by raising the volume of NaOH added from ... JEE Advanced level
• 25.0 mL of a weak monoprotic acid HA requires 20.0 mL of 0.100 M NaOH to reach its equivalence point. After adding 8.0 mL of the same NaOH, the pH is 4.45. Calc... JEE Advanced level
• 20.0 mL of 0.10 M Na2CO3 is titrated with 0.10 M HCl (pK_a1 = 6.35, pK_a2 = 10.33 for H2CO3). Select the correct statements. (Use the amphiprotic formula where ... JEE Advanced level
• 0.10 M acetic acid is titrated with 0.10 M aqueous ammonia, taking K_a(CH3COOH) = K_b(NH3) = 1.8x10^-5. Select the correct statements. JEE Advanced level
• 25.0 mL of 0.10 M NH3 (K_b = 1.8x10^-5) is titrated with 0.10 M HCl. Indicator ranges: methyl red 4.2-6.3; phenolphthalein 8.3-10.0. Select the correct statemen... JEE Advanced level
• Which indicator is most suitable for the titration of aqueous ammonia against hydrochloric acid? NEET level
• 20 mL of benzoic acid (K_a = 6.3x 10^-5) is exactly half-neutralised by NaOH. The pH of the solution is NEET level
• 20 mL of 0.10 M HCl is titrated with 0.10 M NaOH. After 10 mL of NaOH have been added the pH of the mixture is NEET level
• 25 mL of 0.10 M acetic acid (K_a = 1.8x 10^-5) is titrated with 0.10 M NaOH. At the equivalence point the pH is closest to NEET level
• 25.0 mL of 0.100 M CH3COOH (pK_a = 4.74) is titrated with 0.100 M NaOH. The pH after 10.0 mL of NaOH has been added is JEE Main level
• 20.0 mL of 0.100 M NH3 (K_b = 1.8x 10^-5) is titrated with 0.100 M HCl. The pH at the equivalence point is JEE Main level
• 20.0 mL of 0.100 M HCl is titrated with 0.100 M NaOH. The pH after 30.0 mL of NaOH has been added is JEE Main level
• NH3 (K_b = 1.8x 10^-5) at 0.10 M is titrated with 0.10 M HCl, and the equivalence-point pH is 5.28. Which indicator is best suited? JEE Main level
• 20.0 mL of 0.100 M acetic acid (pK_a = 4.74) is titrated with 0.100 M NaOH. What volume of NaOH (in mL) has been added when the pH is 5.00? Use Henderson's equa... JEE Main level
• An acid-base indicator HIn has pK_in = 5.3. At what pH is 80% of the indicator present in the ionised form In-? (Use log 2 = 0.301 and give two decimals.) JEE Main level
• 25.0 mL of 0.100 M acetic acid (K_a = 1.8x 10^-5, pK_a = 4.74) is titrated with 0.100 M NaOH. Which statements are correct? JEE Main level
• 25.0 mL of 0.100 M Na2CO3 is titrated with 0.100 M HCl. For carbonic acid pK_a1 = 6.35 and pK_a2 = 10.33. The pH after 35.0 mL of HCl have been added is JEE Advanced level
• 25.0 mL of a solution that is 0.100 M in HCl and 0.100 M in acetic acid (pK_a = 4.74) is titrated with 0.100 M NaOH. The pH after 30.0 mL of NaOH have been adde... JEE Advanced level
• 20.0 mL of a monoprotic weak acid HA of unknown concentration is titrated with a standard NaOH solution. The pH is 4.28 after 10.0 mL of titrant and 4.76 after ... JEE Advanced level
• 50.0 mL of 0.100 M acetic acid (K_a = 1.8x 10^-5) is titrated with 0.100 M NaOH using an indicator that changes colour at pH 7.00. Take the end point as pH = 7.... JEE Advanced level
• 25.0 mL of 0.100 M diprotic acid H2A (pK_a1 = 4.0, pK_a2 = 9.0) is titrated with 0.100 M NaOH. Treat the two steps as well separated and use Henderson's equatio... JEE Advanced level
• 25.0 mL of 0.100 M methylamine, CH3NH2 (K_b = 4.4x 10^-4), is titrated with 0.100 M HCl. Use [OH-] = sqrtK_bC for the initial solution and Henderson's equation ... JEE Advanced level
• 50.0 mL of 0.100 M acetic acid (K_a = 1.8x 10^-5) is titrated with 0.100 M NaOH. The steep part of the curve extends from the point 99.9% neutralised to the poi... JEE Advanced level