Đáp án đúng: B
Giải chi tiết:\(\begin{array}{l}{n_{C{H_3}N{H_2}}} = 0,32\,mol\\\,\,\,\,\,\,\,\,\,\,\,C{H_3}N{H_2} + HCl \to C{H_3}N{H_3}Cl\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0,32\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \to \,\,\,\,\,\,\,\,\,0,32\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(mol)\\ \Rightarrow {m_{muoi}} = {m_{C{H_3}N{H_3}Cl}} = 21,6\,gam.\end{array}\)
Đáp án B