Đáp án:
\(\begin{array}{l} a,\ m_{Mg}=7,2\ g.\\ m_{Zn}=13\ g.\\ b,\ m_{\text{muối}}=55,7\ g.\\ c,\ V_{H_2}=11,2\ lít.\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l} a,\ PTHH:\\ Mg+2HCl\to MgCl_2+H_2↑\ (1)\\ Zn+2HCl\to ZnCl_2+H_2↑\ (2)\\ m_{Zn}=20,2\times 64,36\%=13\ g.\\ m_{Mg}=20,2-13=7,2\ g.\\ b,\ n_{Zn}=\dfrac{13}{65}=0,2\ mol.\\ n_{Mg}=\dfrac{7,2}{24}=0,3\ mol.\\ Theo\ pt\ (1):\ n_{MgCl_2}=n_{Mg}=0,3\ mol.\\ ⇒m_{MgCl_2}=0,3\times 95=28,5\ g.\\ Theo\ pt\ (2):\ n_{ZnCl_2}=n_{Zn}=0,2\ mol.\\ ⇒m_{ZnCl_2}=0,2\times 136=27,2\ g.\\ ⇒m_{\text{muối}}=m_{MgCl_2}+m_{ZnCl_2}=28,5+27,2=55,7\ g.\\ c,\ ∑n_{H_2}=n_{Mg}+n_{Zn}=0,2+0,3=0,5\ mol.\\ ⇒V_{H_2}=0,5\times 22,4=11,2\ lít.\end{array}\)
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