HCl k có phần trăm à

a) $n_{Fe} = \dfrac{11,2}{56} = 0,2(mol)$
$Fe + 2HCl \to FeCl_2 + H_2$
$n_{HCl} =2 n_{Fe} = 0,2.2 = 0,4(mol)$
$C\%_{HCl} = \dfrac{0,4.36,5}{200}.100\% = 7,3\%$

b) $n_{H_2} = n_{FeCl_2} = n_{Fe} = 0,2(mol)

Sau phản ứng, $m_{dd} = 11,2 + 200 - 0,2.2 = 210,8(gam)$
$C\%_{FeCl_2} = \dfrac{0,2.127}{210,8}.100\% = 12,05\%$

Bài 6:

\(n_{Fe\left(OH\right)_3}=\dfrac{21,4}{107}=0,2\left(mol\right)\)

PT: \(Fe\left(OH\right)_3+3HCl\rightarrow FeCl_3+3H_2O\)

_______0,2________0,6______0,2 (mol)

a, \(C\%_{HCl}=\dfrac{0,6.36,5}{200}.100\%=10,95\%\)

b, \(C\%_{FeCl_3}=\dfrac{0,2.162,5}{21,4+200}.100\%\approx14,68\%\)

Bài 7:

\(m_{H_2SO_4}=100.9,8\%=9,8\left(g\right)\Rightarrow n_{H_2SO_4}=\dfrac{9,8}{98}=0,1\left(mol\right)\)

PT: \(ZnO+H_2SO_4\rightarrow ZnSO_4+H_2O\)

______0,1______0,1_______0,1 (mol)

a, \(m_{ZnO}=0,1.81=8,1\left(g\right)\)

b, \(C\%_{ZnSO_4}=\dfrac{0,1.161}{8,1+100}.100\%\approx14,89\%\)

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

1.

\(m_{HCl}=\dfrac{10,95.75}{100}=8,2125\left(g\right)\)

\(\Rightarrow n_{HCl}=\dfrac{8,2125}{35,5}=0,225\left(mol\right)\)

\(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)

\(\Rightarrow n_{Fe_2O_3}=\dfrac{1}{6}n_{HCl}=0,0375\left(mol\right)\)

\(n_{FeCl_3}=\dfrac{1}{3}n_{HCl}=0,075\left(mol\right)\)

\(\Rightarrow C\%=\dfrac{0,075.162,5}{0,0375.160+75}.100\%=15,05\%\)

2.

\(n_{Al_2O_3}=0,1\left(mol\right);n_{HCl}=0,8\left(mol\right)\)

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

Dễ thấy HCl dư.

\(\Rightarrow n_{AlCl_3}=2n_{Al_2O_3}=0,2\left(mol\right)\)

\(\Rightarrow m_{AlCl_3}=26,7\left(g\right)\)

\(\Rightarrow C\%=\dfrac{26,7}{10,2+200}.100\%=12,7\%\)

\(a,n_{Al_2O_3}=\dfrac{20,4}{102}=0,2\left(mol\right)\\ PTHH:Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\\ .......0,2......1,2......0,4.....0,6\left(mol\right)\\ V_{H_2O\left(đktc\right)}=0,6\cdot22,4=13,44\left(l\right)\\ b,m_{HCl}=36,5\cdot1,2=43,8\left(g\right)\\ c,m_{dd_{HCl}}=1,2\cdot36,5=43,8\left(g\right)\\ C\%_{dd_{HCl}}=\dfrac{43,8}{200}\cdot100\%=21,9\%\)

\(d,m_{AlCl_3}=0,4\cdot133,5=53,4\left(g\right)\\ m_{dd\left(sau.pứ\right)}=m_{Al_2O_3}+m_{dd_{HCl}}-m_{H_2}=20,4+200-10,8=209,6\left(g\right)\\ C\%_{dd_{AlCl_3}}=\dfrac{53,4}{209,6}\cdot100\%\approx25,48\%\)

d)\(m_{NaOH}=\dfrac{mct.C\%}{100}=\dfrac{100.20}{100}=20\left(g\right)\)=>\(n_{NaOH}=\dfrac{20}{40}=0,5\left(mol\right)\)

\(HCl+NaOH\rightarrow NaCl+H_2O\)

tl1............1.............1..............1(mol)

So sánh\(\dfrac{n_{NaOH}}{1}< \dfrac{n_{HCl}}{1}\left(\dfrac{0,5}{1}< \dfrac{1,2}{1}\right)\)

=> HCl Dư

Vậy Dung dịch sau phản ứng làm quỳ tím chuyển màu đỏ

Chúc cậu học tốt nhee

a, \(Mg+2HCl\rightarrow MgCl_2+H_2\)

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

Theo PT: \(n_{HCl}=2n_{Mg}=0,2\left(mol\right)\Rightarrow C\%_{HCl}=\dfrac{0,2.36,5}{400}.100\%=1,825\%\)

c, Theo PT: \(n_{MgCl_2}=n_{H_2}=n_{Mg}=0,1\left(mol\right)\)

Ta có: m _{dd sau pư} = 2,4 + 400 - 0,1.2 = 402,2 (g)

\(\Rightarrow C\%_{MgCl_2}=\dfrac{0,1.95}{402,2}.100\%\approx2,36\%\)

`n_[Zn]=13/65=0,2(mol)`

`Zn + 2HCl -> ZnCl_2 + H_2 \uparrow`

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

`a)V_[H_2]=0,2.22,4=4,48(l)`

`b)C%_[HCl]=[0,4.36,5]/150 .100~~9,73%`

Ta có: \(m_{HCl}=300.7,3\%=21,9\left(g\right)\Rightarrow n_{HCl}=\dfrac{21,9}{36,5}=0,6\left(mol\right)\)

PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\)

___0,3_____0,6_____0,3____0,3 (mol)

a, m_Mg = 0,3.24 = 7,2 (g)

b, Ta có: m _{dd sau pư} = m_Mg + m _{dd HCl} - m_H2 = 7,2 + 300 - 0,3.2 = 306,6 (g)

\(\Rightarrow C\%_{MgCl_2}=\dfrac{0,3.95}{306,6}.100\%\approx9,3\%\)

Bạn tham khảo nhé!

pthh:Mg+2HCl→MgCl2+H2(1)

theo pthh=>\(nMg=\dfrac{1}{2}nHCL=\dfrac{300.7,3\%}{7,3}.\dfrac{1}{2}=\dfrac{3.1}{2}=1,5mol\)

=>mMg=\(1,5.24=36g\)

b, theo pthh(1)\(=>nMgCl2=\dfrac{1}{2}nHCL=1,5mol\)

\(=>mMgCl2=\)\(1,5.95=142,5g\)

\(mdd=\text{ m Mg + mdd HCl - m H2}=36+300-1,5.2=333g\)

\(=>\%mMgCl2=\dfrac{142,5}{333}.100\%=42,8\%\)

\(n_{CaCO_3}=\dfrac{10}{100}=0,1\left(mol\right)\)

a.

\(CaCO_3+2HNO_3\rightarrow Ca\left(NO_3\right)_2+H_2O+CO_2\)

0,1             0,2               0,1                        0,1

\(C\%_{dd.HNO_3}=\dfrac{0,2.63.100}{200}=6,3\%\)

b.

\(m_{dd.Ca\left(NO_3\right)_2}=10+200-0,1.44=205,6\left(g\right)\)

\(C\%_{dd.Ca\left(NO_3\right)_2}=\dfrac{0,1.164.100}{205,6}=7,98\%\)