`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%`

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

\(n_{H_2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\\ a.Zn+2HCl\rightarrow ZnCl_2+H_2\\ 0,05.........0,1..........0,05..........0,05\left(mol\right)\\ a.C\%_{ddHCl}=\dfrac{0,1.36,5}{200}.100=1,825\%\\ b.m_{Zn}=0,05.65=3,25\left(g\right)\\ c.C\%_{ddZnCl_2}=\dfrac{136.0,05}{3,25+200-0,05.2}.100\approx3,347\%\)

lấy 2,1g Zn trong 200ml HCL 1M, thu được dung dịch sau phản ứng. Tính nồng độ phần trăm của dung dịch đó

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nZn= 2,1/ 65(mol) nHCl= 0,2(mol)

PTHH: Zn + 2 HCl -> ZnCl2 + H2 2,1/65 : 1 < 0,2/1

=> HCl dư, tính theo nZn

-> nZnCl2= nZn= 2,1/65 => mZnCl2= 2,1/65 x 136\(\approx4,394\left(g\right)\)

mddZnCl2= mZn+ mddHCl - mH2= 2,1+ 1,18.200 - 2,1/65 . 2\(\approx238,035\left(g\right)\) (Với D(ddHCl)= 1,18g/ml)

=> \(C\%ddZnCl2=\frac{4,394}{238,035}.100\approx1,846\%\)

n Zn= 19,5/65=0,3 (mol).

PTPƯ: Zn(0.3) +   HCl(0.6) ---->  ZnCl2(0.3) + H2(0,3)

mHCl=0,6.36.5=21.9(g)

a) C%HCl= 21.9/300.100%=7,3%

b) VH2=0,3.22,4=6,72(lít)

c) mH2=0,3.2=0,6(g)

mZnCl2=0,3.136=40,8(g)

mddZnCl2 =(19,5+300)-0,6=318,9(g)

C%=mZnCl2/mddZnCl2.100= 40,8/318,9.100=12,793%

PTHH: Zn + 2HCL ---> ZnCl2 + H2

a)Theo bài ta có:

nZn=mZn/MZn=13/65=0,2 mol

=> nHCl=2 nZn=2.0,2=0,4 mol

=>mHCl=n_HCl.M_HCl =0,4 . 36,5=14,6(g)

mdd HCl=D.Vdd=1,14 .200=228(g)

=> C% ddHCl=\(\dfrac{mHCl.100\%}{mddHCl}=\dfrac{14,6.100\%}{228}=6,4\%\)(xấp xỉ)

b) nZnCl2=nZn=0,2 mol

=> mZnCl2= nZnCl2.M_ZnCl2=0,2 .136=27,7(g)

`a)PTHH:`

`Zn + 2HCl -> ZnCl_2 + H_2`

`0,1`    `0,2`            `0,1`        `0,1`             `(mol)`

`n_[HCl]=0,2.1=0,2(mol)`

 `=>m_[Zn]=0,1.65=6,5(g)`

`b)m_[dd HCl]=1,1.200=220(g)`

`=>C%_[ZnCl_2]=[0,1.136]/[6,5+220-0,1.2].100~~6%`

\(a,n_{HCl}=0,2.1=0,2\left(mol\right)\)

PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)

            0,1<--0,2------>0,1------->0,1

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

\(b,m_{ddHCl}=200.1,1=220\left(g\right)\)

\(\rightarrow m_{dd}=220+6,5-0,1.2=226,3\left(g\right)\\ \rightarrow C\%_{ZnCl_2}=\dfrac{0,1.136}{226,3}.100\%=6\%\)

a, \(Mg+2HCl\rightarrow MgCl_2+H_2\)

b, \(n_{Mg}=\dfrac{1,2}{24}=0,05\left(mol\right)\)

Theo PT: \(n_{HCl}=2n_{Mg}=0,1\left(mol\right)\Rightarrow m_{ddHCl}=\dfrac{0,1.36,5}{10\%}=36,5\left(g\right)\)

c, \(n_{H_2}=n_{MgCl_2}=n_{Mg}=0,05\left(mol\right)\)

Ta có: m _{dd sau pư} = 1,2 + 36,5 - 0,05.2 = 37,6 (g)

\(\Rightarrow C\%_{MgCl_2}=\dfrac{0,05.95}{37,6}.100\%\approx12,63\%\)

\(n_{CaCl_2}=\dfrac{22.2}{111}=0.2\left(mol\right)\)

\(m_{dd_{Na_2SO_3}}=200\cdot1.55=310\left(g\right)\)

\(CaCl_2+Na_2SO_3\rightarrow CaSO_3+2NaCl\)

\(0.2................................0.2.............0.4\)

\(m_{CaSO_3}=0.2\cdot120=24\left(g\right)\)

\(m_{NaCl}=0.4\cdot58.5=23.4\left(g\right)\)

\(m_{\text{dung dịch sau phản ứng}}=22.2+310-24=308.2\left(g\right)\)

\(C\%_{NaCl}=\dfrac{23.4}{308.2}\cdot100\%=7.59\%\)