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30 tháng 9 2018

Mg + 2HCl → MgCl2 + H2 (1)

MgO + 2HCl → MgCl2 + H2O (2)

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

Theo PT1: \(n_{Mg}=n_{H_2}=0,1\left(mol\right)\)

\(\Rightarrow m_{Mg}=0,1\times24=2,4\left(mol\right)\)

\(\Rightarrow m_{MgO}=4,4-2,4=2\left(g\right)\)

\(\Rightarrow\%Mg=\dfrac{2,4}{4,4}\times100\%=54,55\%\)

\(\%MgO=\dfrac{2}{4,4}\times100\%=45,45\%\)

Theo PT1: \(n_{HCl}=2n_{Mg}=2\times0,1=0,2\left(mol\right)\)

\(n_{MgO}=\dfrac{2}{40}=0,05\left(mol\right)\)

Theo PT2: \(n_{HCl}=2n_{MgO}=2\times0,05=0,1\left(mol\right)\)

\(\Rightarrow\Sigma n_{HCl}=0,1+0,2=0,3\left(mol\right)\)

\(\Rightarrow C_{M_{HCl}}=\dfrac{0,3}{0,3}=1\left(M\right)\)

Theo PT1,2: \(\Sigma n_{MgCl_2}=\dfrac{1}{2}\Sigma n_{HCl}=\dfrac{1}{2}\times0,3=0,15\left(mol\right)\)

\(\Rightarrow C_{M_{MgCl_2}}=\dfrac{0,15}{0,3}=0,5\left(M\right)\)

22 tháng 10 2018

Mg + 2HCl → MgCl2 + H2 (1)

MgO + 2HCl → MgCl2 + H2O (2)

nH2=2,2422,4=0,1(mol)nH2=2,2422,4=0,1(mol)

Theo PT1: nMg=nH2=0,1(mol)nMg=nH2=0,1(mol)

⇒mMg=0,1×24=2,4(mol)⇒mMg=0,1×24=2,4(mol)

⇒mMgO=4,4−2,4=2(g)⇒mMgO=4,4−2,4=2(g)

⇒%Mg=2,44,4×100%=54,55%⇒%Mg=2,44,4×100%=54,55%

%MgO=24,4×100%=45,45%%MgO=24,4×100%=45,45%

Theo PT1: nHCl=2nMg=2×0,1=0,2(mol)nHCl=2nMg=2×0,1=0,2(mol)

nMgO=240=0,05(mol)nMgO=240=0,05(mol)

Theo PT2: nHCl=2nMgO=2×0,05=0,1(mol)nHCl=2nMgO=2×0,05=0,1(mol)

⇒ΣnHCl=0,1+0,2=0,3(mol)⇒ΣnHCl=0,1+0,2=0,3(mol)

⇒CMHCl=0,30,3=1(M)⇒CMHCl=0,30,3=1(M)

Theo PT1,2: ΣnMgCl2=12ΣnHCl=12×0,3=0,15(mol)ΣnMgCl2=12ΣnHCl=12×0,3=0,15(mol)

⇒CMMgCl2=0,150,3=0,5(M)

30 tháng 9 2018

Mg + 2HCl → MgCl2 + H2 (1)

MgO + 2HCl → MgCl2 + H2O (2)

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

Theo PT1: \(n_{Mg}=n_{H_2}=0,1\left(mol\right)\)

\(\Rightarrow m_{Mg}=0,1\times24=2,4\left(g\right)\)

\(\Rightarrow m_{MgO}=4,4-2,4=2\left(g\right)\)

\(\Rightarrow\%Mg=\dfrac{2,4}{4,4}\times100\%=54,55\%\)

\(\%MgO=\dfrac{2}{4,4}\times100\%=45,45\%\)

Theo PT1: \(n_{HCl}=2n_{Mg}=2\times0,1=0,2\left(mol\right)\)

\(n_{MgO}=\dfrac{2}{40}=0,05\left(mol\right)\)

Theo PT2: \(n_{HCl}=2n_{MgO}=2\times0,05=0,1\left(mol\right)\)

\(\Rightarrow\Sigma n_{HCl}=0,2+0,1=0,3\left(mol\right)\)

\(\Rightarrow C_{M_{HCl}}=\dfrac{0,3}{0,3}=1\left(M\right)\)

Theo PT1,2: \(\Sigma n_{MgCl_2}=\dfrac{1}{2}\Sigma n_{HCl}=\dfrac{1}{2}\times0,3=0,15\left(mol\right)\)

\(\Rightarrow C_{M_{MgCl_2}}=\dfrac{0,15}{0,3}=0,5\left(M\right)\)

nH2=0,1(mol)

PTHH: Mg + 2 HCl -> MgCl2 + H2

0,1__________0,2___________0,1(mol)

MgO + 2 HCl -> MgCl2 + H2O

0,05____0,1___0,05(mol)

mMg=0,1. 24= 2,4(g) -> mMgO=4,4-2,4= 2(g) -> nMgO=0,05((mol)

b) %mMg= (2,4/4,4).100=54,545%

=> %mMgO=45,455%

c) nHCl=0,3(mol) -> mHCl=0,3.36,5=10,95(g)

=> mddHCl=(10,95.100)/7,3=150(g)

25 tháng 12 2023

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

a.

\(CuO+2HCl\rightarrow CuCl_2+H_2O\)

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

b.

\(n_{Mg}=n_{H_2}=0,1\left(mol\right)\Rightarrow m_{Mg}=0,1.24=2,4\left(g\right),m_{CuO}=12-2,4=9,6\left(g\right)\)

c. 

\(m_{muối}=m_{CuCl_2}+m_{MgCl_2}=0,12.135+95.0,1=25,7\left(g\right)\)

 

27 tháng 12 2020

PT: \(Mg+H_2SO_4\rightarrow MgSO_4+H_2\left(1\right)\)

\(MgO+H_2SO_4\rightarrow MgSO_4+H_2O\left(2\right)\)

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

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

\(\Rightarrow m_{Mg}=0,1.24=2,4\left(g\right)\)

\(\Rightarrow m_{MgO}=m_{hh}-m_{Mg}=4,4-2,4=2\left(g\right)\)

Bạn tham khảo nhé!

27 tháng 12 2020

cảm  ơn bạn nha. thanks you

 

21 tháng 12 2020

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

             \(MgO+2HCl\rightarrow MgCl_2+H_2O\)

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

\(\Rightarrow m_{Mg}=0,1\cdot24=2,4\left(g\right)\) \(\Rightarrow m_{MgO}=2\left(g\right)\)

21 tháng 12 2020

mg+2hcl-> mgcl2+ h2

mgo+2hcl->mgcl2+ h2o

đặt nmg=a, nmgo=b

theo bài ra và theo pthh ta có hệ:

24a+40b=4,4

a=2,24/22,4

=> a=0,1, b=0,05

-> %m Mg=0,1*24/4,4*100=54,54%

%m MgO=100-54,54=45,45%

13 tháng 10 2021
 

a, 

Mg+ 2HCl= MgCl2+ H2 

MgO+ 2HCl= MgCl2+ H2O

b, 

nH2= 2,24/22,4= 0,1 mol 

=> nMg= nMgCl2= 0,5nHCl= 0,1 mol => nHCl= 0,2 mol 

=> mMg= 0,1.24= 2,4g 

=> mMgO= 2g 

c, 

nMgO= 2/40= 0,05 mol

=> nMgO= 0,5nHCl= nMgCl2= 0,05 mol 

=> nHCl= 0,1 mol 

Tổng lượng HCl cần dùng là 0,1+0,2=0,3 mol 

=> m dd HCl= 0,3.36,5.100:7,3= 150g 

27 tháng 10 2021

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

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

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

\(\Rightarrow m_{Mg}=0,1\cdot24=2,4\left(g\right)\)

\(\Rightarrow m_{MgO}=4,4-2,4=2\left(g\right)\)\(\Rightarrow n_{MgO}=\dfrac{2}{40}=0,05mol\)

\(MgO+2HCl\rightarrow MgCl_2+H_2O\)

0,05       0,1

\(\Rightarrow\Sigma n_{HCl}=0,2+0,1=0,3mol\)\(\Rightarrow m_{HCl}=0,3\cdot36,5=10,95\left(g\right)\)

\(\Rightarrow m_{ddHCl}=\dfrac{10,95}{7,3}\cdot100=150\left(g\right)\)

 

 

1 tháng 11 2021

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

a. PTHH: 

Mg + 2HCl ---> MgCl2 + H2 (1)

MgO + 2HCl ---> MgCl2 + H2O (2)

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

=> \(m_{Mg}=0,1.24=2,4\left(g\right)\)

=> \(m_{MgO}=4,4-2,4=2\left(g\right)\)

b. Ta có: \(n_{MgO}=\dfrac{2}{40}=0,05\left(mol\right)\)

=> \(n_{hh}=0,05+0,1=0,15\left(mol\right)\)

Theo PT(1,2)\(n_{HCl}=2.n_{hh}=2.0,15=0,3\left(mol\right)\)

=> \(V_{dd_{HCl}}=\dfrac{0,3}{0,4}=0,75\left(lít\right)\)