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Bài 1
\(a,n_{CuO}=\dfrac{16}{80}=0,2\left(mol\right)\\ CuO+2HCl\xrightarrow[]{}CuCl_2+H_2O\\ n_{CuCl_2}=n_{CuO}=0,2mol\\ m_{CuCl_2}=0,2.135=27\left(g\right)\\ b.n_{HCl}=0,2.2=0,4\left(mol\right)\\ C_{MHCl}=\dfrac{0,4}{0,5}=0,8\left(M\right)\)
Bài 5
\(a,n_{NaOH}=0,2.1=0,2\left(mol\right)\\ 2NaOH+H_2SO_4\xrightarrow[]{}Na_2SO_4+2H_2O\\ n_{H_2SO_4}=0,2:2=0,1\left(mol\right)\\ C_{MH_2SO_4}=\dfrac{0,1}{0,4}=0,25\left(M\right)\\ b,n_{Na_2SO_4}=0,2:2=0,1\left(mol\right)\\ C_{MNa_2SO_4}=\dfrac{0,1}{0,2+0,4}=\dfrac{1}{6}\left(M\right)\\ c,m_{Na_2SO_4}=0,1.142=14,2\left(g\right)\)
\(ASO_3+H_2SO_4\rightarrow ASO_4+SO_2+H_2O\\ n_{ASO_3}=n_{H_2SO_4}=\dfrac{200.24,5\%}{98}=0,5\left(mol\right)\\ Tacó:M_{ASO_3}=A+32+16.3=\dfrac{10,4}{0,5}=20,8\\ \Rightarrow A=-59,2\)
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\(n_{FeO}=\dfrac{7,2}{72}=0,1mol\\ n_{H_2SO_4}=0,4.1,5=0,6mol\\ FeO+H_2SO_4\rightarrow FeSO_4+H_2O\\ \Rightarrow\dfrac{0,1}{1}< \dfrac{0,6}{1}\Rightarrow H_2SO_4.dư\\ n_{FeO}=n_{FeSO_4}=n_{H_2SO_4,pư}=0,1mol\\ C_{M_{FeSO_4}}=\dfrac{0,1}{0,4}=0,25M\\ C_{M_{H_2SO_4}}=\dfrac{0,6-0,1}{0,4}=1,25M\)
a) $Mg + 2HCl \to MgCl_2 + H_2$
$n_{MgCl_2} = \dfrac{4,75}{95} = 0,05(mol)$
$n_{HCl} = 2n_{MgCl_2} = 0,1(mol)$
$m_{dd\ HCl} = \dfrac{0,1.36,5}{14,6\%} = 25(gam)$
$\Rightarrow V_{dd\ HCl} = \dfrac{25}{1,12} = 22,32(ml)$
b) $n_{Mg} = n_{H_2} = n_{MgCl_2} = 0,05(mol)$
$\Rightarrow m_{dd\ sau\ pư} = 0,05.24 + 25 - 0,05.2 = 26,1(gam)$
$C\%_{HCl} = \dfrac{4,75}{26,1}.100\% = 18,2\%$
a)
\(n_{Fe}=\dfrac{8,4}{56}=0,15\left(mol\right)\)
PTHH: Fe + 2HCl --> FeCl2 + H2
0,15-->0,3----->0,15-->0,15
=> \(V_{H_2}=0,15.22,4=3,36\left(l\right)\)
b) \(m_{FeCl_2}=0,15.127=19,05\left(g\right)\)
c) \(m_{HCl}=0,3.36,5=10,95\left(g\right)\)
=> \(C\%=\dfrac{10,95}{200}.100\%=5,475\%\)
a) CT oxit \(AO\)
\(AO+2HCl\rightarrow ACl_2+H_2\\ n_{HCl}=0,4\left(mol\right)\\ n_A=\dfrac{1}{2}n_{HCl}=0,2\left(mol\right)\\ \Rightarrow M_{AO}=A+16=\dfrac{8}{0,2}=40\\ \Rightarrow A=24\left(Mg\right)\)
b)\(n_{MgSO_3}=\dfrac{10,4}{104}=0,1\left(mol\right)\\ n_{H_2SO_4}=\dfrac{200.24,5\%}{98}=0,5\left(mol\right)\\ MgSO_3+H_2SO_4\rightarrow MgSO_4+SO_2+H_2O\\ LTL:\dfrac{0,1}{1}< \dfrac{0,5}{1}\\ \Rightarrow H_2SO_4dưsauphảnứng\\ n_{H_2SO_4\left(pứ\right)}=n_{SO_2}=n_{MgSO_4}=n_{MgSO_3}=0,1\left(mol\right)\\ n_{H_2SO_4\left(dư\right)}=0,5-0,1=0,4\left(mol\right)\\ m_{ddsaupu}=10,4+200-0,1.64=204\left(g\right)\\ C\%_{MgSO_4}=\dfrac{0,1.120}{204}.100=5,88\%\\ C\%_{H_2SO_4\left(dư\right)}=\dfrac{0,4.98}{204}=19,22\%\)
\(a,n_{AO}=\dfrac{8}{M_A+16}(mol);n_{HCl}=1.0,4=0,4(mol)\\ PTHH:AO+2HCl\to ACl_2+H_2O\\ \Rightarrow n_{AO}=\dfrac{1}{2}n_{HCl}=0,2(mol)\\ \Rightarrow M_{AO}=\dfrac{8}{0,2}=40(g/mol)\\ \Rightarrow M_{A}=40-16=24(g/mol)\\ \text {Vậy A là magie(Mg) và CTHH oxit là }MgO\\\)
\(b,n_{MgSO_3}=\dfrac{10,4}{104}=0,1(mol)\\ m_{H_2SO_4}=\dfrac{200.24,5\%}{100\%}=49(g)\\ \Rightarrow n_{H_2SO_4}=\dfrac{49}{98}=0,5(mol)\\ PTHH:MgSO_3+H_2SO_4\to MgSO_4+SO_2\uparrow +H_2O \)
Vì \(\dfrac{n_{MgSO_3}}{1}<\dfrac{n_{H_2SO_4}}{1}\) nên \(H_2SO_4\) dư
\(\Rightarrow n_{MgSO_4}=n_{SO_2}=n_{H_2O}=n_{MgSO_3}=0,1(mol)\\ \Rightarrow \begin{cases} m_{CT_{MgSO_4}}=0,1.120=12(g)\\ m_{SO_2}=0,1.64=6,4(g)\\ m_{H_2O}=0,1.18=1,8(g) \end{cases}\\ \Rightarrow m_{dd_{MgSO_4}}=10,4+200-6,4-1,8=202,2(g)\\ \Rightarrow C\%_{MgSO_4}=\dfrac{12}{202,2}.100\%\approx 5,93\%\)
a,\(n_{H_2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\)
PTHH: Mg + 2HCl → MgCl2 + H2
Mol: 0,05 0,1 0,05 0,05
PTHH: MgO + 2HCl → MgCl2 + H2O
Mol: 0,1 0,2 0,1
⇒ mMg = 0,05.24 = 1,2 (g)
mMgO = 5,2 - 1,2 = 4 (g)
b,\(n_{MgO}=\dfrac{4}{40}=0,1\left(mol\right)\)
⇒ nHCl đã dùng = 0,1+0,2 = 0,3 (mol)
\(C_{M_{ddHCl}}=\dfrac{0,3}{0,5}=0,6\left(l\right)\)
c,\(C_{M_{MgCl_2}}=\dfrac{0,05+0,1}{0,6}=0,25M\)
a)
\(n_{CuCl_2}=0,1.1,5=0,15\left(mol\right)\)
\(n_{Ca\left(OH\right)_2}=0,3.1=0,3\left(mol\right)\)
PTHH: CuCl2 + Ca(OH)2 --> Cu(OH)2 + CaCl2
Xét tỉ lệ: \(\dfrac{0,15}{1}< \dfrac{0,3}{1}\) => CuCl2 hết, Ca(OH)2 dư
PTHH: CuCl2 + Ca(OH)2 --> Cu(OH)2\(\downarrow\) + CaCl2
_____0,15---->0,15-------->0,15---------->0,15
=> \(\left\{{}\begin{matrix}C_{M\left(Ca\left(OH\right)_2dư\right)}=\dfrac{0,3-0,15}{0,1+0,3}=0,375M\\C_{M\left(CaCl_2\right)}=\dfrac{0,15}{0,1+0,3}=0,375M\end{matrix}\right.\)
b) Khối lượng giảm = khối lượng H2O sinh ra
\(n_{H_2O}=\dfrac{0,9}{18}=0,05\left(mol\right)\)
PTHH: Cu(OH)2 --to--> CuO + H2O
_____0,05<-----------0,05<----0,05
=> mCu(OH)2 = (0,15-0,05).98 = 9,8 (g)
=> mCuO = 0,05.80 = 4(g)
c) \(n_{SO_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
=> \(n_{SO_2\left(pư\right)}=\dfrac{0,15.80}{100}=0,12\left(mol\right)\)
PTHH: Ca(OH)2 + SO2 --> CaSO3\(\downarrow\) + H2O
_____________0,12------>0,12
=> mCaSO3 = 0,12.120 = 14,4(g)
Bài 4 :
\(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)
\(n_{Mg}=\frac{4,8}{24}=0,2\left(mol\right)\)
\(n_{H2SO4}=0,1.6=0,6\left(mol\right)\)
\(\Rightarrow\) Mg hết , H2SO4 dư
\(\Rightarrow\) Sau phản ứng trong dd gồm \(MgSO_4;H_2SO_{4_{dư}}\)
\(n_{MgSO4}=n_{Mg}=0,2\left(mol\right)\)
\(n_{H2SO4_{dư}}=0,6-0,2=0,4\left(mol\right)\)
\(CM_{MgSO4}=\frac{0,2}{0,1}=2M\)
\(CM_{H2SO4}=\frac{0,4}{0,1}=4M\)
Bài 5 :
\(FeO+2HCl\rightarrow FeCl_2+H_2O\)
\(n_{FeO}=\frac{7,2}{72}=0,1\left(mol\right)\)
\(m_{HCl}=\frac{10,95.200}{10}=21,9\left(g\right)\)
\(\Rightarrow n_{HCl}=\frac{21,9}{36,5}=0,6\left(mol\right)\)
\(\Rightarrow\) FeO hết, HCl dư
\(\Rightarrow\) Sau phản ứng trong dung dịch gồm \(FeCl_2;HCl_{dư}\)
\(C\%_{FeCl2}=\frac{0,1.127}{7,2+200}.100\%=6,1\%\)
\(C\%_{HCl}=\frac{0,4.36,4}{7,2+100}.100\%=7\%\)
Bài 5:
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)
\(n_{Al}=\frac{5,4}{27}=0,2\left(mol\right)\)
\(m_{HCl}=\frac{14,6.500}{100}=73\left(g\right)\)
\(n_{HCl}=\frac{73}{36,5}=2\left(mol\right)\)
\(\Rightarrow\) Al hết, HCl dư
\(\Rightarrow\) Dung dịch sau phản ứng gồm \(HCl_{Dư};AlCl_3\)
\(C\%_{AlCl3}=\frac{0,2.133,5}{5,4+500}.100\%=5,3\%\)
\(C\%_{HCl_{Dư}}=\frac{1,4.36,5}{5,4+500}.100\%=10,11\%\)
cảm ơn bạn