A solution is 0.30 m in nh3. what concentration of nh4cl would be required to achieve a buffer solution with a final ph of 9.0? recall the hh equation can be written using ph and pka or poh and pkb. the kb of nh3 is 1.8 x 10–5.
- first, we have to get POH. and when we have PH = 9 so, PH+POH = 14 POH = 14 -9 = 5 - then by using this formula of PKa: PKa = -㏒Kb and when we have Kb = 1.8x10^-5 so by substitution: PKa = - ㏒ 1.8x10^-5 ∴PKa = 4.7 So know we have Pka & POH So by substitution in the following formula w can get the concentration: POH = Pka + ㏒[HB]/[B} 5 = 4.7 + ㏒[HB]/[0.3]
