Question

Which buffer is better able to maintain a steady pH on the addition of small amounts of both a strong acid and strong base? Explain Marks 1 Bupivacaine is the active molecule in some local anaesthetics. Of the two enantiomers, the one shown below (X) is the more effective NH What is the molecular formula of (X)? 2 List the substituents attached to the stereogenic according to the sequence rule. centre in descending order of priority 2 lowest priority highest priority Page Total:

Answer 1

(1) A buffer solution is one in which the pH of the mixture would be maintained constant steadily even with the addition of a small amount of acid or base.

Examples for the buffers are (i) Acidic buffer- Mixture of a weak acid HA) and it's salt with a strong base (conjugate base) (A^-Na⁺); Acetic acid and sodium acetate mixture, whose pH =4.75.

Buffer action:

If you add strong acid HCl, H⁺ ions consumed by CH3COO^- and forms very less dissociating weak acid by increasing pH slightly.

If you add strong Base NaOH, OH^- ions combine with CH3COOH and forms CH3COO^- and H₂O, thereby consuming the OH- ions, in turn there will be no change pH.

(2)Molecular formula of X is C₁₈H₂₈ON₂

_{(3) Stereogenic point and order of priority are in the attached figure.
Slerco ceuti steruogenic ces.lie) decershis orde g CN}