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\(n_{H_2}=\dfrac{8.4}{22,4}=0,375\left(mol\right)\)
\(n_{O_2}=\dfrac{2.8}{22,4}=0,125\left(mol\right)\)
PTHH : 2H2 + O2 -> 2H2O
0,125 0,25
Ta thấy : 0,375 > 0,125 => H2 dư , O2 đủ
\(m_{H_2O}=0,25.18=4,5\left(g\right)\)
\(n_{H_2}=\dfrac{V_{H_2}}{22,4}=\dfrac{8,4}{22,4}=0,375mol\)
\(n_{O_2}=\dfrac{V_{O_2}}{22,4}=\dfrac{2,8}{22,4}=0,125mol\)
\(2H_2+O_2\rightarrow\left(t^o\right)2H_2O\)
0,375 >0,125 ( mol )
0,125 0,25 ( mol )
\(m_{H_2O}=n_{H_2O}.M_{H_2O}=0,25.18=4,5g\)
\(H_2+\dfrac{1}{2}O_2-^{t^o}\rightarrow H_2O\)
\(n_{H_2}=\dfrac{4,47}{22,4}=0,2\left(mol\right)\)
\(n_{H_2O}=n_{H_2}=0,2\left(mol\right)\)
=> \(m_{H_2O}=0,2.18=3,6\left(g\right)\)
\(n_{O_2}=\dfrac{1}{2}n_{H_2}=0,1\left(mol\right)\)
=> \(V_{H_2}=0,1.22,4=2,24\left(l\right)\)
Chắc là 4,48 lít nhở?
nH2=4,48/22,4=0,2(mol)
a) PTHH: H2 + 1/2 O2 -to-> H2O
nH2O=nH2=0,2(mol)
=>mH2O=0,2.18=3,6(g)
=>m=3,6(g)
b) nO2=1/2. 0,2=0,1(mol)
V(O2,đktc)=1/2.22,4=2,24(l)
Chúc em học tốt!
Bài 1:
\(PTHH:2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\\ Zn+H_2SO_4\rightarrow ZnSO_4+H_2\\ n_{NaOH}=\dfrac{6}{40}=0,15\left(mol\right)\\ \Rightarrow n_{H_2SO_4}=\dfrac{1}{2}n_{NaOH}=\dfrac{1}{2}\cdot0,15=0,075\left(mol\right)\\ \Rightarrow m=m_{H_2SO_4}=0,075\cdot98=7,35\left(g\right)\\ n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\\ \Rightarrow n_{H_2}=0,2\left(mol\right)\\ \Rightarrow V=V_{H_2}=0,2\cdot22,4=4,48\left(l\right)\)
PTHH: \(2KClO_3\xrightarrow[MnO_2]{t^o}2KCl+3O_2\uparrow\)
\(S+O_2\xrightarrow[]{t^o}SO_2\)
Ta có: \(n_{KClO_3}=\dfrac{18,375}{122,5}=0,15\left(mol\right)\) \(\Rightarrow n_{O_2\left(lý.thuyết\right)}=0,225\left(mol\right)\)
\(\Rightarrow n_{O_2\left(thực\right)}=0,225\cdot85\%=0,19125\left(mol\right)=n_S=n_{SO_2}\)
\(\Rightarrow\left\{{}\begin{matrix}V_{O_2}=0,19125\cdot22,4=4,284\left(l\right)=V_{SO_2}\\m_S=0,19125\cdot32=6,12\left(g\right)\\\end{matrix}\right.\)
nO2=0,3mol
pthh: S+O2=>SO2
0,3<-0,3->0,3
=> m=0,3.32=9,6g
V=0,3.22,4=6,72l
a) \(n_{O_2}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)
PTHH: 2KMnO4 --to--> K2MnO4 + MnO2 + O2
1<-----------------------------0,5
=> \(m_{KMnO_4}=1.158=158\left(g\right)\)
b) \(n_{Fe_2O_3}=\dfrac{80}{160}=0,5\left(mol\right)\)
PTHH: Fe2O3 + 3H2 --to--> 2Fe + 3H2O
0,5--->1,5
=> \(V_{H_2}=1,5.22,4=33,6\left(l\right)\)
c) \(n_{CuO}=\dfrac{8}{80}=0,1\left(mol\right)\)
\(n_{H_2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\)
PTHH: CuO + H2 --to--> Cu + H2O
Xét tỉ lệ: \(\dfrac{0,1}{1}>\dfrac{0,05}{1}\) => CuO dư, H2 hết
PTHH: CuO + H2 --to--> Cu + H2O
0,05<-0,05---->0,05-->0,05
=> \(n_{Cu\left(dư\right)}=0,1-0,05=0,05\left(mol\right)\)
mCu = 0,05.64 = 3,2 (g)
VH2O = 0,05.22,4 = 1,12 (l)
a)\(n_{O_2}=\dfrac{11,2}{22,4}=0,5mol\)
\(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)
1 0,5
\(M_{KMnO_4}=1\cdot158=158g\)
b)\(n_{Fe_2O_3}=\dfrac{80}{160}=0,5mol\)
\(Fe_2O_3+3H_2\rightarrow2Fe+3H_2O\)
0,5 1,5
\(V_{H_2}=1,15\cdot22,4=25,76l\)
\(a) Fe + 2HCl \to FeCl_2 + H_2\\ n_{H_2} = n_{Fe} = \dfrac{5,6}{56} = 0,1(mol)\\ \Rightarrow V_{H_2} = 0,1.22,4 = 2,24(lít)\\ b) n_{O_2} = \dfrac{6,72}{22,4} = 0,3(mol)\\ 2H_2 + O_2 \xrightarrow{t^o} 2H_2O\\ \dfrac{n_{H_2}}{2} = 0,05 < \dfrac{n_{O_2}}{1} = 0,3 \to O_2\ dư\\ n_{H_2O} = n_{H_2} = 0,1(mol) \Rightarrow m_{H_2O} = 0,1.18 = 1,8(gam)\)
