Đáp án:

Gọi `[CH_3COOC_2H_5]_{bđ}=[H_2O]_{bđ}=x(M)`

Ta có:

`[CH_3COOC_2H_5]_{pứ}=[H_2O]_{pứ}=[CH_3COOH]_{pứ}=[C_2H_5OH]_{pứ}=0,42(M)`

`=>[CH_3COOC_2H_5]_{cb}=[H_2O]_{cb}=(x-0.42)`

`=>K_C={ [C_2H_5OH].[CH_3COOH]}/{[CH_3COOC_2H_5].[H_2O]}={(0,42)^2}/{(x-0,42)^2}=0,27`

`=>x~~1,228`

`=>[CH_3COOC_2H_5]_{cb}=1,228-0,42=0,808(M)`