Acid-base titrations and double titration (NaOH, Na2CO3, NaHCO3)

36 questions on Acid-base titrations and double titration (NaOH, Na2CO3, NaHCO3) from the Equivalent Concept and Titration chapter: 7 NEET level, 14 JEE Main, 15 JEE Advanced. Each one opens with its answer and solution.

• A solution of pure Na2CO3 is titrated with standard HCl. If the phenolphthalein end point is reached after adding V_1 mL, the methyl orange end point (total vol... NEET level
• 20 mL of 0.2 M NaOH is neutralised by 0.05 M H2SO4. The volume of acid required is: NEET level
• In the titration of aqueous HCl against aqueous ammonia (strong acid with weak base), the most suitable indicator is: NEET level
• 1.325 g of pure Na2CO3 (molar mass 106 g mol^-1) is titrated with 0.500 M HCl. Select the correct statement(s). JEE Main level
• A 25.0 mL aliquot of a solution containing only NaOH and Na2CO3 is titrated with 0.100 M HCl. The phenolphthalein end point needs 20.0 mL and a further 5.0 mL t... JEE Main level
• A solution contains only Na2CO3 and NaHCO3. It is titrated with 0.100 M HCl: the phenolphthalein end point is reached after 12.0 mL and the methyl orange end po... JEE Main level
• A solution contains a single solute (or a mixture) from NaOH, Na2CO3, NaHCO3. On titration with HCl, the volume to the phenolphthalein end point (V_1) equals th... JEE Main level
• 0.756 g of oxalic acid dihydrate H2C2O4.2H2O (molar mass 126 g mol^-1) is dissolved in water and made up to 100 mL. A 10.0 mL portion needs 12.5 mL of a NaOH so... JEE Main level
• A 1.25 g sample of impure NaOH (impurity is neutral to HCl) is dissolved in water and neutralised by 36.4 mL of 0.500 N HCl. The percentage purity of the sample... JEE Main level
• A 250 mL flask holds a solution of NaOH and Na2CO3. A 25.0 mL aliquot is titrated with 0.1000 M HCl: the phenolphthalein end point is at 21.4 mL and the methyl ... JEE Advanced level
• A 20.0 mL sample containing only Na2CO3 and NaHCO3 is titrated with 0.150 M HCl. The phenolphthalein end point is at 9.6 mL. After that, a further 24.4 mL is ne... JEE Advanced level
• Four samples are each titrated with the same HCl. The burette readings are noted at the phenolphthalein end point (R_1) and at the methyl orange end point (R_2)... JEE Advanced level
• A 0.900 g sample of limestone (only CaCO3 reacts with acid) is treated with 40.0 mL of 0.500 N HCl. The excess acid requires 24.0 mL of 0.250 N NaOH for back ti... JEE Advanced level
• A solution contains H3PO4 and NaH2PO4. Titration with 0.100 M NaOH needs 12.0 mL to reach the methyl orange end point (first stage, H3PO4 -> H2PO4-) and a total... JEE Advanced level
• An aliquot contains H2C2O4 and NaHC2O4 only. It needs 42.0 mL of 0.150 N NaOH for complete neutralisation and, in a separate identical aliquot, 45.0 mL of 0.200... JEE Advanced level
• 25.0 mL of a saturated filtered solution of Ca(OH)2 requires 20.0 mL of 0.0400 M HCl for neutralisation. Assuming complete dissociation, the solubility product ... JEE Advanced level
• A 50.0 mL sample of a mixture of HCl and H2SO4 gives 0.699 g of BaSO4 (molar mass 233 g mol^-1) with excess BaCl2. A separate 25.0 mL portion needs 42.0 mL of 0... JEE Advanced level
• A 25.0 mL sample containing only NaOH and/or Na2CO3 and/or NaHCO3 is titrated with 0.100 M HCl. The phenolphthalein end point is at 14.0 mL and a further 6.0 mL... JEE Advanced level
• In the titration of Na2CO3 solution against standard HCl, the colour change of phenolphthalein (pink to colourless) marks the stage at which the carbonate has b... NEET level
• How many mL of 0.200 M NaOH are required to neutralise exactly 20.0 mL of 0.100 M HCl? NEET level
• What volume of 0.100 M H2SO4 is needed to neutralise 20.0 mL of 0.100 M NaOH completely? NEET level
• 25.0 mL of 0.100 M Na2CO3 is titrated with 0.100 M HCl using methyl orange (end point = complete conversion to CO2). The volume of HCl needed is: NEET level
• 50.0 mL of 0.200 M HCl is mixed with 30.0 mL of 0.200 M NaOH. Assuming volumes are additive, the pH of the resulting solution is (take log 2 = 0.301): JEE Main level
• 20.0 mL of a Na2CO3 solution needs 12.0 mL of 0.100 M HCl to reach the phenolphthalein end point. The molarity of the Na2CO3 solution is: JEE Main level
• 30.0 mL of 0.0600 M Na2CO3 is titrated with 0.150 M HCl to the methyl orange end point. The volume of HCl required is: JEE Main level
• 25.0 mL of saturated lime water (Ca(OH)2) needs 18.0 mL of 0.0500 M HCl for neutralisation. Using molar mass 74 g/mol, the solubility of Ca(OH)2 in g/L is: JEE Main level
• 0.265 g of pure anhydrous Na2CO3 (106 g/mol) is dissolved in water and titrated with a HCl solution to the methyl orange end point, requiring 22.0 mL. Find the ... JEE Main level
• 0.630 g of H2C2O4.2H2O (molar mass 126 g/mol) is dissolved in water to make 100 mL. A 10.0 mL portion needs 13.0 mL of NaOH solution for complete neutralisation... JEE Main level
• 1.50 g of impure CaCO3 (molar mass 100 g/mol) is treated with 50.0 mL of 0.500 M HCl. The excess acid requires 18.0 mL of 0.250 M NaOH in a back titration. Find... JEE Main level
• Choose the correct statements about indicator choice in acid-base titrations (phenolphthalein: pH range about 8.3-10; methyl orange: about 3.1-4.4). JEE Main level
• A solution contains only NaOH and Na2CO3. Titrated with HCl, phenolphthalein is decolourised after 20.0 mL; methyl orange is then added and a further 7.5 mL is ... JEE Advanced level
• A mixture of Na2CO3 (106 g/mol) and NaHCO3 (84 g/mol) is titrated with 0.100 M HCl. The phenolphthalein end point is reached after 15.0 mL and, after adding met... JEE Advanced level
• 1.50 g of a solid containing NaOH, Na2CO3 and inert matter is dissolved in water and made up to 250 mL. A 25.0 mL aliquot needs 22.0 mL of 0.100 M HCl to reach ... JEE Advanced level
• In a Kjeldahl determination, the ammonia from 0.500 g of an organic compound is absorbed in 50.0 mL of 0.100 M H2SO4. The unreacted acid needs 21.0 mL of 0.200 ... JEE Advanced level
• A solution is known to contain NaOH, Na2CO3 and NaHCO3 in at most two-component combinations. Titration with HCl gives V1 mL to the phenolphthalein end point an... JEE Advanced level
• 25.0 mL portions of the following 0.100 M solutions are titrated with 0.100 M HCl. Which statements are correct? JEE Advanced level