Take pK_a(H2CO3) = 6.4. Which of the following acids liberate CO2 from aqueous NaHCO3? (pK_a values: 2,4,6-trinitrophenol 0.4; 2-nitrobenzoic acid 2.17; 4-nitrophenol 7.15; phenol 10.0.)

JEE Main levelOne or more correct optionsDifficulty 2 of 3g2123

Take $p K_{a} (H X_{2} CO X_{3}) = 6.4$ . Which of the following acids liberate $CO X_{2}$ from aqueous $NaHCO X_{3}$ ? ( $p K_{a}$ values: 2,4,6-trinitrophenol 0.4; 2-nitrobenzoic acid 2.17; 4-nitrophenol 7.15; phenol 10.0.)

CO X_{2}

is released only if the acid is stronger than

H X_{2} CO X_{3}

(6.4). 2,4,6-Trinitrophenol (0.4) and 2-nitrobenzoic acid (2.17) qualify. 4-Nitrophenol (7.15;

lo g K = 6.4 - 7.15 = - 0.75

) and phenol (10.0) are weaker than carbonic acid.