The pK_a of a weak acid (HA) is 4.5. The pOH of an aqueous buffered solution of HA in which 50 % of the acid is ionized is

The pK_a of a weak acid (HA) is 4.5. The pOH of an aqueous buffered so

1.	The pK_a of a weak acid (HA) is 4.5. The pOH of an aqueous buffered solution of HA in which 50 % of the acid is ionized is
Answer» `7.0` `4.5` `2.5` `9.5` SOLUTION :For acidic buffer, `pH=pK_a+"LOG" ([A^-])/([HA])` When the ACID is 50% ionised , `[A^-]=[HA]` or pH=`pK_a+log 1` or pH = `pK_a` Given `pK_a=4.5` `therefore` pH=9.5 `therefore` pOH=14-4.5=9.5