题目

Chemistry problems!Help!
1.Calculate the pH when we add 0.001 mole of HAc to 0.02 mole of NaAc and bring the volume up to 100ml with pure water.
HAc ↔ H+ + Ac− pKa = 4.76
2.Consider the following two systems:
(a) 0.1 litre of pure water at pH 7.0
(b) 0.1 litre of 0.1M phosphate buffer at pH 7.2
H2PO4 ↔ HPO42− + H+ pKa = 7.2
If we add 10ml of 0.01 M HCl to each,what will be the pH in each solution.
p/s:Solve the questions,not translate it for me!Thanks!
I need the answer in English,please..Help!

提问时间：2020-11-02

答案

1.suppose [H+]=x mol/Lbefore ionization[HAc]=0.01mol/L [Ac-]=0.2mol/LHAc ↔ H+ + Ac− before 0.01 0 0.2after 0.01-x x 0.2+xthus -lg[(0.2+x)*x/(0.01-x)]=4.76note that x is quite smalltherefor...