For an acetic acid - acetate buffer ($\mathrm{p}{K}_a=4.74$), the ratio $[\mathrm{CH}{}_3\mathrm{COO}{}^{-}]/[\mathrm{CH}{}_3\mathrm{COOH}]$ needed for pH = 5.04 is (use $\log 2=0.301$)

More questions on Buffer solutions and Henderson equation

• 50 mL of 0.2 M weak acid HA (pK_a = 4.70) is mixed with 50 mL of 0.1 M NaA. Use log 2 = 0.301. The pH of the mixture is JEE Main level
• To 1 L of a buffer containing 0.10 M CH3COOH and 0.10 M CH3COONa (pK_a = 4.74), 0.01 mol of solid NaOH is added (no volume change). The new ... JEE Main level
• A solution contains 0.30 M NH3 and 0.15 M NH4Cl. Given pK_b(NH3) = 4.74, log 2 = 0.301 and pK_w = 14, its pH is JEE Main level
• 100 mL of 0.30 M CH3COOH is mixed with 100 mL of 0.10 M NaOH. With pK_a = 4.74 and log 2 = 0.301, the pH is JEE Main level
• Sodium acetate (molar mass 82 g/mol) is to be dissolved in 1.0 L of 0.10 M acetic acid so that the pH is pK_a + 0.477 (log 3 = 0.477). The m... JEE Main level
• To 1 L of buffer containing 0.20 M CH3COOH and 0.20 M CH3COONa (pK_a = 4.74), 0.02 mol HCl gas is added without volume change. The new pH is JEE Main level