\(a.Fe+2HCl\rightarrow FeCl_2+H_2\\b.n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\\ n_{H_2}=n_{Fe}=0,1\left(mol\right)\\ \Rightarrow V_{H_2}=0,1.22,4=2,24\left(l\right)\\ c.n_{FeCl_2}=n_{Fe}=0,1\left(mol\right)\\ m_{FeCl_2}=0,1.127=12,7\left(g\right) \)

a)\(m_{ddHCl}=\dfrac{4,8}{10\%}.100\%=48\left(g\right)\)

b)\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)

\(PTHH:Mg+2HCl\xrightarrow[]{}MgCl_2+H_2\)

\(n_{MgCl_2}=n_{Mg}=n_{H_2}=0,2\)

\(m_{MgCl_2}=0,2.95=19\left(g\right)\)

\(V_{H_2}=0,2.22,4=4.48\left(l\right)\)

c)\(m_{H_2}=0,2.2=0,4\left(g\right)\)

\(m_{ddMgCl_2}=4,8+48-0,4=52,4\left(g\right)\)

\(C\%_{MgCl_2}=\dfrac{19}{52,4}.100\%=36\%\)

a.b.\(n_{Mg}=\dfrac{4,8}{24}=0,2mol\)

\(n_{HCl}=\dfrac{18,25}{36,5}=0,5mol\)

\(Mg+2HCl\rightarrow MgCl_2+H_2\)

0,2  <   0,5                               ( mol )

0,2       0,4             0,2        0,2      ( mol )

\(m_{HCl\left(dư\right)}=\left(0,5-0,4\right).36,5=3,65g\)

\(V_{H_2}=0,2.22,4=4,48l\)

c.Cách 1:

\(m_{MgCl_2}=0,2.95=19g\)

Cách 2:

\(m_{H_2}=0,2.2=0,4g\)

\(m_{HCl}=0,4.36,5=14,6g\)

Áp dụng ĐL BTKL, ta có:

\(m_{Mg}+m_{HCl}=m_{MgCl_2}+m_{H_2}\)

\(\Rightarrow m_{MgCl_2}=4,8+14,6-0,4=19g\)

a, \(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ n_{HCl}=\dfrac{18,25}{36,5}=0,5\left(mol\right)\)

PTHH: Mg + 2HCl ---> MgCl₂ + H₂

LTL: \(0,2< \dfrac{0,5}{2}\)=> HCl dư

\(\left\{{}\begin{matrix}n_{H_2}=n_{MgCl_2}=0,2\left(mol\right)\\n_{HCl\left(pư\right)}=0,2.2=0,4\left(mol\right)\end{matrix}\right.\\ \Rightarrow m_{dư}=\left(0,5-0,4\right).36,5=3,65\left(g\right)\)

b, V_H2 = 0,2.22,4 = 4,48 (l)

c, C1: \(m_{MgCl_2}=0,2.95=19\left(g\right)\)

C2: Bảo toàn khối lượng:

\(m_{MgCl_2}=4,8+0,4.36,5-0,2.2=19\left(g\right)\)

\(Mg+2HCl\rightarrow MgCl_2+H_2\\ n_{Mg}=\dfrac{2,4}{24}=0,1\left(mol\right)\\ n_{H_2}=n_{MgCl_2}=n_{Mg}=0,1\left(mol\right)\\ a,V_{H_2\left(đktc\right)}=0,1.22,4=2,24\left(l\right)\\ b,m_{MgCl_2}=95.0,1=9,5\left(g\right)\\ c,m_{ddMgCl_2}=m_{Mg}+m_{ddHCl}-m_{H_2}=2,4+200-0,1.2=202,2\left(g\right)\\ C\%_{ddMgCl_2}=\dfrac{9,5}{202,2}.100\approx4,698\%\\ d,n_{CuO}=\dfrac{16}{80}=0,2\left(mol\right)\\ PTHH:H_2+CuO\rightarrow\left(t^o\right)Cu+H_2O\\ Vì:\dfrac{0,2}{1}>\dfrac{0,1}{1}\Rightarrow CuOdư\\ n_{CuO\left(dư\right)}=0,2-0,1.1=0,1\left(mol\right)\\ m_{CuO\left(dư\right)}=0,1.80=8\left(g\right)\)

a. \(PTHH:Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)

\(n_{Mg}=\dfrac{m_{Mg}}{M_{Mg}}=\dfrac{12}{24}=0,5\left(mol\right)\)

- Mol theo PTHH : \(1:2:1:1\)

- Mol theo phản ứng : \(0,5\rightarrow1\rightarrow0,5\rightarrow0,5\)

\(\Rightarrow n_{H_2}=0,5\left(mol\right)\)

\(\Rightarrow V_{H_2}=n_{H_2}.22,4=0,5.22,4=11,2\left(l\right)\)

b. Từ a. \(\Rightarrow n_{HCl}=1\left(mol\right)\)

\(\Rightarrow m_{HCl}=n_{HCl}.M_{HCl}=1.\left(1+35,5\right)=36,5\left(g\right)\)

c. \(n_{O_2}=\dfrac{V_{O_2}}{22,4}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

\(PTHH:2H_2+O_2\underrightarrow{t^o}2H_2O\)

- Mol theo PTHH : \(2:1:2\)

- Mol theo phản ứng : \(0,6\leftarrow0,3\rightarrow0,6\)

\(\Rightarrow n_{H_2O}=0,6\left(mol\right)\)

\(\Rightarrow m_{H_2O}=n_{H_2O}.M_{H_2O}=0,6.\left(2+16\right)=10,8\left(g\right)\)

a) PTHH: Zn+2HCl-------t^o----> ZnCl₂+H₂

n_Zn=\(\dfrac{m}{M}=\dfrac{32,5}{65}=0,5\left(mol\right)\)

---> \(n_{H_2}\)=0,5(mol)

b)\(V_{H_2}\)=n.22,4=0,5.22,4=11,2(lít)

c)\(n_{ZnCl_2}\)=0,5(mol)

\(m_{ZnCl_2}\)=n.M=0,5.136=68(gam)

\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

\(n_{Al}=\dfrac{3,375}{27}=0,125\)

\(\Rightarrow n_{H_2}=\dfrac{0,125}{2}.3=0,1875mol\)      \(\Rightarrow V_{H_2}=0,1875.22,4=4,2l\)

\(n_{AlCl_3}=n_{Al}=0,125mol\)       \(\Rightarrow m_{AlCl_3}=0,125.133,5=16,6875g\)

a) Zn + 2HCl →ZnCl₂  + H₂

b) nZn = 6,5/65 = 0,1 mol . Theo tỉ lệ pư => nH₂ = nZn = nZnCl₂ =0,1 mol <=> V_H2(đktc) = 0,1.22,4 = 2,24 lít.

c) mZnCl₂ = 0,1 . 136 = 13,6 gam

d) nHCl =2nZn = 0,2 mol => mHCl = 0,2.36,5= 7,3 gam

Cách 2: áp dụng định luật BTKL => mHCl = mZnCl₂ + mH₂ - mZn 

<=> mHCl = 13,6 + 0,1.2 - 6,5 = 7,3 gam