21.
a) $CH_3-CH=CH_2+Br_2\xrightarrow{}CH_3-CHBr-CH_2Br$
b) $CH≡CH+2AgNO_3+2NH_3\xrightarrow{t^o}AgC≡CAg+2NH_4NO_3$
c) $C_6H_5OH+NaOH\xrightarrow{}C_6H_5ONa+\dfrac{1}{2}H_2$
d) $C_4H_9OH+CuO\xrightarrow{t^o}C_3H_7CHO+Cu+H_2O$
22.
a)
$C_2H_5OH+Na\xrightarrow{}C_2H_5ONa+\dfrac{1}{2}H_2$
$x$ : $x$ : $x$ : $\dfrac{1}{2}x$ (mol)
$C_6H_5OH+Na\xrightarrow{}C_6H_5ONa+\dfrac{1}{2}H_2$
$y$ : $y$ : $y$ : $\dfrac{1}{2}y$ (mol)
Gọi $n_{C_2H_5OH}$ và $n_{C_6H_5OH}$ lần lượt là x và y (mol)
Ta có $n_{H_2}=\dfrac{1}{2}x+\dfrac{1}{2}y=\dfrac{1,68}{22,4}=0,075(mol)(1)$
$m_{hh}=46x+94y=11,3(g)(2)$
$(1),(2)=> x=\dfrac{7}{120}(mol),y=\dfrac{11}{120}(mol)$
%$m_{C_2H_5OH}=\dfrac{\dfrac{7}{120}.46}{11,3}.100≈23,75$%
%$m_{C_6H_5OH}=100-23,75=76,25$%
