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nZn = 0,2 (mol)
nHCl = 0,5 (mol)
Zn + 2HCl \(\rightarrow\) ZnCl2 + H2
bđ 0,2 0,5 (mol)
pư 0,2 \(\rightarrow\) 0,4 \(\rightarrow\) 0,2 -----> 0,2 (mol)
spư 0 .......0,1.....0,2...........0,2 (mol)
a) mZnCl2 = 27,2 (g)
b)VH2=4,48 (l)
c) NaOH + HCl \(\rightarrow\) NaCl + H2O
0,1 <--- 0,1 (mol)
VNaOH = \(\frac{0,1}{0,5}\) = 0,2 (l) = 200 ml
200ml = 0,2l
\(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\)
Pt : \(Zn+2HCl\rightarrow ZnCl_2+H_2|\)
1 2 1 1
0,3 0,6 0,3 0,3
a) \(n_{ZnCl2}=\dfrac{0,3.1}{1}=0,3\left(mol\right)\)
\(C_{M_{ZnCl2}}=\dfrac{0,3}{0,2}=1,5\left(M\right)\)
b) \(n_{H2}=\dfrac{0,3.1}{1}=0,3\left(mol\right)\)
\(V_{H2\left(dktc\right)}=0,3.22,4=6,72\left(l\right)\)
c) Pt : \(NaOH+HCl\rightarrow NaCl+H_2O|\)
1 1 1 1
0,6 0,6
\(n_{NaOH}=\dfrac{0,6.1}{1}=0,6\left(mol\right)\)
\(m_{NaOH}=0,6.40=24\left(g\right)\)
\(m_{ddNaOH}=\dfrac{24.100}{20}=120\left(g\right)\)
Chúc bạn học tốt
đổi 500ml = 0,5l
n(CH\(_3\)COOH)\(_2\)Mg= \(\dfrac{14,2}{142}\)= 0,1mol
2CH3COOH + Mg \(\rightarrow\) (CH3COO)2Mg + H2
0,2mol 0,1mol 0,1mol
a/ CCH3COOH= \(\dfrac{0,2}{0,5}\)=0,4M
b/ VH\(_2\) 0,1 . 22,4 = 2,24l
c/ nCH\(_3\)COOH= 0,2mol
CH3COOH + NaOH \(\rightarrow\) CH3COONa + H2
0,2mol 0,2mol
V\(_{dd_{NaOH}}\)= \(\dfrac{0,2}{0,5}\)= 0,4l
\(a) Zn +2 CH_3COOH \to (CH_3COO)_2Zn + H_2\\ b) n_{H_2} = n_{Zn} = \dfrac{13}{65} = 0,2(mol)\\ V_{H_2} = 0,2.22,4 = 4,48(lít)\\ n_{CH_3COOH} = 2n_{Zn} = 0,4(mol) \Rightarrow V_{dd\ CH_3COOH} = \dfrac{0,4}{1} = 0,4(lít)\\ c) C_2H_5OH + O_2 \xrightarrow{men\ giấm} CH_3COOH + H_2O\\ n_{C_2H_5OH\ pư} = n_{CH_3COOH} = 0,4(mol)\\ m_{C_2H_5OH\ cần dùng} = \dfrac{0,4.46}{90\%} = 20,44(gam)\)
\(a,PTHH:Zn+2HCl\rightarrow ZnCl_2+H_2\\ b,n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\\ n_{HCl}=2\cdot0,15=0,3\left(mol\right)\)
Vì \(\dfrac{n_{Zn}}{1}>\dfrac{n_{HCl}}{2}\) nên sau p/ứ Zn dư
\(\Rightarrow n_{Zn}=\dfrac{1}{2}n_{HCl}=0,15\left(mol\right)\\ \Rightarrow m_{Zn}=0,15\cdot65=9,75\\ \Rightarrow m_{Zn\left(dư\right)}=13-9,75=3,25\left(g\right)\\ c,n_{H_2}=n_{Zn}=0,15\left(mol\right)\\ \Rightarrow V_{H_2}=0,15\cdot22,4=3,36\left(l\right)\)
\(a.H_2SO_{\text{4}}+2NaOH\rightarrow Na_2SO_4+2H_2O\left(1\right)\\ H_2SO_4+Fe\rightarrow FeSO_4+H_2\left(2\right)\\ n_{Fe}=\dfrac{19,04}{56}=0,34\left(mol\right)\\ n_{H_2}=n_{Fe}=0,34\left(mol\right)\\ \Rightarrow V_{H_2}=0,34.22,4=7,616\left(mol\right)\\ b.n_{H_2SO_4\left(2\right)}=n_{Fe}=0,34\left(mol\right)\\ n_{H_2SO_4\left(bđ\right)}=0,5.1=0,5\left(mol\right)\\ \Rightarrow n_{H_2SO_4\left(1\right)}=0,5-0,34=0,16\left(mol\right)\\ Tacó:n_{NaOH}=2n_{H_2SO_4 }=0,32\left(mol\right)\\ \Rightarrow V_{NaOH}=\dfrac{0,32}{0,5}=0,64\left(l\right)\)
1. B
2. B
(Câu 2 cậu nên sửa lại câu hỏi nhé: Khối lượng dung dịch NaOH 10% ...)
Câu 1.
\(n_{Fe}=\dfrac{5,6}{56}=0,1mol\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
0,1 0,1
\(V_{H_2}=0,1\cdot22,4=2,24\left(l\right)\)
Chọn B.
Câu 2. \(n_{HCl}=0,2\cdot1=0,2mol\)
Để trung hòa: \(\Rightarrow n_{H^+}=n_{OH^-}=0,2\)
\(m_{NaOH}=0,2\cdot40=8\left(g\right)\)
\(m_{ddNaOH}=\dfrac{8}{10\%}\cdot100\%=80\left(g\right)\)
Chọn B.
1) nZn=13/65=0,2(mol)
PTHH: Zn + 2 HCl -> ZnCl2 + H2
nH2=nZnCl2=nZn=0,2(mol)
nHCl=2.0,2=0,4(mol)
=> mHCl=0,4 x 36,5=14,6(g)
=> mddHCl=(14,6.100)/8=182,5(g)
2) V(H2,đktc)=0,2 x 22,4= 4,48(l)
mZnCl2=0,2.136=27,2(g)
3) mddsau=mZn+mddHCl - mH2= 13+182,5-0,2.2=195,1(g)
4) C%ddZnCl2=(27,2/195,1).100=13,941%
\(pt:zn+2HCl\rightarrow ZnCl_2+H_2\)
a,theo đề bài ta có : \(n_{zn}=\frac{13}{65}=0.2\left(mol\right),n_{hcl}=1.0,5=0,5\left(mol\right)\)
ta thấy hcl dư vì: \(\frac{n_{hcl}}{2}>\frac{n_{zn}}{1}\)
theo phương trình \(n_{zncl_2}=n_{zn}=0,2\left(mol\right)\Rightarrow m_{zncl_2}=0,2.127=25,4\left(mol\right)\)
b,\(n_{h_2}=n_{zn}=0,2\left(mol\right)\Rightarrow V_{hcl}=0,2.22,4=4,48\left(l\right)\)
c,theo phương trình \(n_{hcl_{pu}}=2n_{zn}=0,4\left(mol\right)\Rightarrow n_{hcl_{du}}=n_{hcl_{bandau}}-n_{pu}=0,5-0,4=0.1\left(mol\right)\)
\(pt:NaOH+HCl\rightarrow NaCl+H_2\)
\(\Rightarrow n_{NaOH}=n_{hcl}=0.1\Rightarrow V_{dd}=\frac{0.1}{0.5}=0.2\left(l\right)\)
bạn ơi cho mk hỏi là sao NAOH ra 0,1 mol