Calculate the amount of NH_(3) and NH_(4)Cl required to prepare a buffer solution of pH 9.0 when total concentration of buffering reagents is 0.6 mol L^(-1). pK_(b) for NH_(3)=4.7, log 2 = 0.30.

Calculate the amount of NH_(3) and NH_(4)Cl required to prepare a buff

1.	Calculate the amount of NH_(3) and NH_(4)Cl required to prepare a buffer solution of pH 9.0 when total concentration of buffering reagents is 0.6 mol L^(-1). pK_(b) for NH_(3)=4.7, log 2 = 0.30.
Answer» Solution :`pH = 9.0 `. Hence, `pOH = 14-9 = 5 ` `pOH = pK_(b) + log. (["SALT"])/(["BASE"])` `5=4.7+ log. (["Salt"])/(["Base"]) orlog. (["Salt"])/(["Base"]) = 0.3 or(["Salt"])/(["Base"]) = Antilog 0.3 = 2, i.e.,["Salt"]=2xx["Base"]` Also. We are given : [Salt]+ [Base] = 0.6 mol `L^(-1)` This on solving gives [Base] = 0.2 mol `L^(-1)` and [Salt]=0.4 mol `L^(-1)`