a) nZn=0,3(mol

PTHH: 2 Zn + O2 -to-> 2 ZnO

b) nZnO=nZn=0,3(mol)

=>mZnO=81.0,3= 24,3(g)

c) nO2= nZn/2= 0,3/2=0,15(mol)

Số phân tử khí oxi đã p.ứ: 0,15.6.10²³=9.10²² (phân tử)

a. \(n_{Zn}=\dfrac{6.5}{65}=0,1\left(mol\right)\)

PTHH : Zn + 2HCl -> ZnCl₂ + H₂

            0,1      0,2                  0,1

b. \(V_{H_2}=0,1.22,4=2,24\left(l\right)\)

c. \(m_{HCl}=0,2.36,5=7,3\left(g\right)\)

\(n_{Zn}=\dfrac{6,5}{65}=0,1mol\)

\(Zn+2HCl\rightarrow ZnCl_2+H_2\)

0,1      0,2                       0,1

\(V_{H_2}=0,1\cdot22,4=2,24l\)

\(m_{HCl}=0,2\cdot36,5=7,3g\)

PTHH: \(Zn+\dfrac{1}{2}O_2\xrightarrow[]{t^o}ZnO\)

Bảo toàn khối lượng: \(m_{O_2}=m_{ZnO}-m_{Zn}=1,6\left(g\right)\)

a. \(2Zn+O_2\rightarrow2ZnO\)

b.\(m_{Zn}+m_{O_2}\rightarrow m_{ZnO}\)

\(\Rightarrow6,5+m_{O_2}=8,1\)

\(\Rightarrow m_O=8,1-6,5=1,6\)

\(n_{Zn}=\dfrac{13}{65}=0,2(mol)\\ a,PTHH:Zn+2HCl\to ZnCl_2+H_2\\ b,n_{HCl}=2n_{Zn}=0,4(mol)\\ \Rightarrow m_{HCl}=0,4.36,5=14,6(g)\\ c,n_{H_2}=n_{Zn}=0,2(mol)\\ \Rightarrow V_{H_2}=0,2.22,4=4,48(l)\)

b) mHCl = 14,6 (g)

V H2 = 4,48 (l)

Giải thích các bước:

a) PTHH:  Zn +  2HCl → ZnCl2 + H2↑

b) nZn = 13 : 65 = 0,2 mol

Theo PTHH: nHCl = 2.nZn = 0,4 mol

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

c) nH2 = nZn = 0,2 mol

VH2 = 0,2 . 22,4 = 4,48 (l)

PT: Fe2O3+3H2to→2Fe+3H2O

CuO+H2to→Cu+H2O

a, Ta có:  mFe2O3=20.60%=12(g)

⇒nFe2O3=\(\dfrac{12}{160}\)=0,075(mol

mCuO=20−12=8(g

⇒nCuO=\(\dfrac{8}{80}\)=0,1(mol)

Theo pT: 

nFe=2nFe2O3=0,15(mol)

nCu=nCuO=0,1(mol)

⇒mFe=0,15.56=8,4(g)

mCu=0,1.64=6,4(g)

b, Theo PT: nH2=3nFe2O3+nCuO=0,325(mol)

⇒VH2=0,325.22,4=7,28(l)

c. Zn+2HCl->ZnCl2+H2

               0,65----------0,325

=>m HCl=0,65.36,5=23,725g

Ủa bạn cái câu a . 20x60% ( 20 ở đâu vậy bạn

a, \(FeO+H_2\underrightarrow{t^o}Fe+H_2O\)

b, \(n_{FeO}=\dfrac{7,2}{72}=0,1\left(mol\right)\)

\(n_{Fe}=n_{FeO}=0,1\left(mol\right)\Rightarrow m_{Fe}=0,1.56=5,6\left(g\right)\)

c, \(n_{H_2}=n_{FeO}=0,1\left(mol\right)\Rightarrow V_{H_2}=0,1.22,4=2,24\left(l\right)\)

\(n_{Zn}=\dfrac{m}{M}=\dfrac{16,25}{65}=0,25\left(mol\right)\\ PTHH:Zn+H_2SO_4->ZnSO_4+H_2\)

tỉ lệ        1     :     1       :       1            :  1

n(mol)     0,25-->0,25------->0,25------>0,25

\(V_{H_2\left(dktc\right)}=n\cdot22,4=0,25\cdot22,4=5,6\left(l\right)\\ m_{ZnSO_4}=n\cdot M=0,25\cdot\left(65+32+16\cdot4\right)=40,25\left(g\right)\)

Bài 1:

\(a,PTHH:Zn+H_2SO_4\to ZnSO_4+H_2\\ b,m_{Zn}+m_{H_2SO_4}=m_{ZnSO_4}+m_{H_2}\\ c,m_{H_2SO_4}=32,2+0,4-13=19,6(g) \)

Bài 2:

 Bảo toàn KL: \(m_{Zn}+m_{HCl}=m_{ZnCl_2}+m_{H_2}\)

\(\Rightarrow m_{H_2}=6,5+7,3-13,6=0,2(g)\)

Bài 3:

Bảo toàn KL: \(m_{Mg}+m_{O_2}=m_{MgO}\)

\(\Rightarrow m_{O_2}=1000-600=400(g)\)