nH2 = 2.24/22.4 = 0.1 (mol) 

Zn + 2HCl => ZnCl2 + H2 

ZnO + 2HCl => ZnCl2 + H2O 

nZn = nH2 = 0.1 (mol) 

=> mZn = 6.5 g

mZnO = 14.6 - 6.5 = 8.1 (g) 

nZnO = 0.1 (mol)  

%Zn = 6.5/14.6 * 100% = 44.52%

%ZnO = 55.48%

nHCl = 0.1*2 + 0.1*2= 0.4 (mol) 

Vdd HCl = 0.4 / 0.5 = 0.8 l 

C32: 

a, \(n_C=\dfrac{2,4}{12}=0,2\left(mol\right)\)

PT: \(C+O_2\underrightarrow{t^o}CO_2\)

Theo PT: \(n_{CO_2}=n_C=0,2\left(mol\right)\Rightarrow V_{CO_2}=0,2.22,4=4,48\left(l\right)\)

b, \(n_{NaOH}=0,3.1=0,3\left(mol\right)\)

\(\Rightarrow\dfrac{n_{NaOH}}{n_{CO_2}}=1,5\) → Pư tạo NaHCO₃ và Na₂CO₃

PT: \(CO_2+NaOH\rightarrow NaHCO_3\)

\(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)

Ta có: \(\left\{{}\begin{matrix}n_{CO_2}=n_{NaHCO_3}+n_{Na_2CO_3}=0,2\\n_{NaOH}=n_{NaHCO_3}+2n_{Na_2CO_3}=0,3\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}n_{NaHCO_3}=0,1\left(mol\right)\\n_{Na_2CO_3}=0,1\left(mol\right)\end{matrix}\right.\)

⇒ m_NaHCO3 = 0,1.84 = 8,4 (g)

m_Na2CO3 = 0,1.106 = 10,6 (g)

c, \(C_{M_{NaHCO_3}}=C_{M_{Na_2CO_3}}=\dfrac{0,1}{0,3}=\dfrac{1}{3}\left(M\right)\)

Lần sau bạn đăng tách câu hỏi ra nhé.

C31:

a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

\(ZnO+2HCl\rightarrow ZnCl_2+H_2O\)

b, \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

Theo PT: \(n_{Zn}=n_{H_2}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,1.65}{14,6}.100\%\approx44,52\%\\\%m_{ZnO}\approx55,48\%\end{matrix}\right.\)

c, \(n_{ZnO}=\dfrac{14,6-0,1.65}{81}=0,1\left(mol\right)\)

Theo PT: \(n_{HCl}=2n_{Zn}+2n_{ZnO}=0,4\left(mol\right)\)

\(\Rightarrow m_{ddHCl}=\dfrac{0,4.36,5}{10\%}=146\left(g\right)\)

\(n_{H_2}=\dfrac{2,24}{22,4}=0,1=n_{Zn}\\ n_{ZnO}=\dfrac{14,6-6,5}{81}=0,1mol\\ C\%=\dfrac{0,2\cdot136}{175,6+14,6-0,2}=14,32\%\)

nH2=0,1mol

Zn + 2HCl -----> ZnCl2 + H2

0,1 mol 0,1 mol

mZn=0,1.65=6,5g

mZnO=14,6-6,5=8,1g

%mZn=\(\frac{6,5}{14,6}\).100=44,5%

%mZnO=55,5%

\(n_{H2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

Pt : \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2|\)

         1           1              1           1

         0,1       0,1                         0,1

         \(ZnO+H_2SO_4\rightarrow ZnSO_4+H_2O|\)

           1             1              1                1

          0,1          0,1

a) \(n_{Zn}=\dfrac{0,1.1}{1}=0,1\left(mol\right)\)

\(m_{Zn}=0,1.65=6,5\left(g\right)\)

\(m_{ZnO}=14,6-6,5=8,1\left(g\right)\)

b) Có : \(m_{MgO}=8,1\left(g\right)\)

\(n_{ZnO}=\dfrac{8,1}{81}=0,1\left(mol\right)\)

\(n_{H2SO4\left(tổng\right)}=0,1+0,1=0,2\left(mol\right)\)

\(V_{ddH2SO4}=\dfrac{0,2}{2}=0,1\left(l\right)\)

 Chúc bạn học tốt

\(n_{Zn}=\dfrac{26}{65}=0,4\left(mol\right)\\ pthh:Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\) 
           0,4       0,8        0,4           0,4
\(a,V_{H_2}=0,4.22,4=8,96\left(l\right)\\ b,C\%_{HCl}=\dfrac{0,8.36,5}{150}.100\%=19,5\%\\ c,m_{\text{dd}}=26+150-\left(0,4.2\right)=175,2\left(g\right)\\ C\%_{ZnCl_2}=\dfrac{0,4.136}{175,2}.100\%=31\%\)

a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

\(ZnO+2HCl\rightarrow ZnCl_2+H_2O\)

b, Ta có: \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

Theo PT: \(n_{Zn}=n_{H_2}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,1.65}{10}.100\%=65\%\\\%m_{ZnO}=35\%\end{matrix}\right.\)

c, \(n_{HCl}=0,1.0,5=0,05\left(mol\right)\)

\(n_{NaOH}=0,03.1=0,03\left(mol\right)\)

PT: \(HCl+NaOH\rightarrow NaCl+H_2O\)

Xét tỉ lệ: \(\dfrac{0,05}{1}>\dfrac{0,03}{1}\), ta được HCl dư.

→ Quỳ tím chuyển đỏ do acid dư.

a, PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)

b, Ta có: \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

Theo PT: \(n_{Zn}=n_{H_2}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,1.65}{20}.100\%=32,5\%\\\%m_{Al_2O_3}=67,5\%\end{matrix}\right.\)

c, Ta có: m_Al2O3 = 20 - 0,1.65 = 13,5 (g)

\(\Rightarrow n_{Al_2O_3}=\dfrac{13,5}{102}=\dfrac{9}{68}\left(mol\right)\)

Theo PT: \(n_{HCl}=2n_{Zn}+6n_{Al_2O_3}=\dfrac{169}{170}\left(mol\right)\)

\(\Rightarrow V_{ddHCl}=\dfrac{\dfrac{169}{170}}{1}\approx0,994\left(l\right)\)

d, Theo PT: \(\left\{{}\begin{matrix}n_{ZnCl_2}=n_{Zn}=0,1\left(mol\right)\\n_{AlCl_3}=2n_{Al_2O_3}=\dfrac{9}{34}\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_{ZnCl_2}=0,1.136=13,6\left(g\right)\\m_{AlCl_3}=\dfrac{9}{34}.133,5\approx35,34\left(g\right)\end{matrix}\right.\)

\(n_{H2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

Pt : \(Fe+2HCl\rightarrow FeCl_2+H_2|\)

        1         2              1           1

       0,1       0,2                        0,1

\(n_{Fe}=\dfrac{0,1.1}{1}=0,1\left(mol\right)\)

⇒ \(m_{Fe}=0,1.56=5,6\left(g\right)\)

\(n_{HCl}=\dfrac{0,1.2}{1}=0,2\left(mol\right)\)

200ml = 0,2l

\(C_{M_{ddHCl}}=\dfrac{0,2}{0,2}=1\left(M\right)\)

⇒ Chọn câu : A 

 Chúc bạn học tốt