220) The pH of blood is 7.4. If the buffer in blood is CO₂ and HCO₃⁻, then the ratio of conjugate base to acid (H₂CO₃) to maintain the pH of the blood will be:

221) 1 L of saturated solution of MgCl₂ is evaporated to dryness, due to which 20 mg of residue is left. What is the solubility product of MgCl₂ of that solution?

222) 10 mL of 0.2M acid is added to 250 mL of a buffer solution with pH = 6.34. The pH of the solution becomes 6.32. The buffer capacity of the solution is:

223) Heat of neutralisation when 200 mL of 0.1M HCl is mixed with 300 mL of 0.2M NaOH will be:

224) To 100 mL of 2M aniline, 100 mL of 2M HCl solution is added. pH of the final solution at 25^oC is: