Đáp án + giải thích các bước giải:
1. `2C_2H_5OH+2K \to 2C_2H_5OK+H_2↑`
2. `C_2H_4(OH)_2+2Na \to C_2H_4(ONa)_2+H_2↑`
3. $C_2H_5OH+HBr \xrightarrow{t^o}C_2H_5Br+H_2O$
4. $C_2H_5OH+C_2H_5OH \xrightarrow[140^oC]{H_2SO_4đ} C_2H_5OC_2H_5+H_2O$
5. $CH_3CH_2OH \xrightarrow[170^oC]{H_2SO_4đ} CH_2=CH_2+H_2O$