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)

a)

\(n_{HCl}=\dfrac{200.14,6}{100.36,5}=0,8\left(mol\right)\)

\(n_{CO_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

PTHH: MgCO₃ + 2HCl --> MgCl₂ + CO₂ + H₂O

______a--------->2a-------->a-------->a

CaCO₃ + 2HCl --> CaCl₂ + CO₂ + H₂O

_b-------->2b-------->b------->b

=> \(\left\{{}\begin{matrix}84a+100b=28,4\\a+b=0,3\end{matrix}\right.=>\left\{{}\begin{matrix}a=0,1\\b=0,2\end{matrix}\right.\)

=> \(\left\{{}\begin{matrix}\%MgCO_3=\dfrac{0,1.84}{28,4}.100\%=29,577\%\\\%CaCO_3=\dfrac{0,2.100}{28,4}.100\%=70,423\%\end{matrix}\right.\)

b) m_{dd sau pư} =  28,4 + 200 - 0,3.44 = 215,2 (g)

\(\left\{{}\begin{matrix}C\%\left(MgCl_2\right)=\dfrac{0,1.95}{215,2}.100\%=4,4\%\\C\%\left(CaCl_2\right)=\dfrac{0,2.111}{215,2}.100\%=10,32\%\\C\%\left(HCl\right)=\dfrac{\left(0,8-2.0,1-2.0,2\right).36,5}{215,2}.100\%=3,39\%\end{matrix}\right.\)

a, Ta có : \(n_{CO2}=\dfrac{V}{22,4}=0,1\left(mol\right)\)

\(BTNT\left(C\right):n_{MgCO3}=n_{CO2}=0,1\left(mol\right)\)

\(\Rightarrow m_{MgCO3}=n.M=8,4\left(g\right)\)

\(\Rightarrow m_{MgO}=8\left(g\right)\)

b, Thấy sau khi phản ứng xảy ra thu được dung dịch A gồm \(MgSO_4\) và có thể còn \(H_2SO_4\) dư .

\(BTNT\left(Mg\right):n_{MgSO_4}=n_{MgCO3}+n_{MgO}=0,3\left(mol\right)\)

\(PTHH:MgSO_4+Ba\left(OH\right)_2\rightarrow Mg\left(OH\right)_2\downarrow+BaSO_4\downarrow\)

.................0,3............0,3..................0,3..................0,3.............

\(\Rightarrow m_{\downarrow}=m_{Mg\left(OH\right)2}+m_{BaSO4}=87,3\left(g\right)\)

Mà \(\left\{{}\begin{matrix}m\downarrow=110,6\left(g\right)>87,3g\\n_{Ba\left(OH\right)2}=C_M.V=0,45>n_{Ba\left(OH\right)2pu}\left(0,3mol\right)\end{matrix}\right.\)

=> Dung dịch A vẫn còn H2SO4 dư và mol BaSO4 được tạo ra tiếp là :

\(n_{BaSO4}=\dfrac{110,6-87,3}{M}=0,1\left(mol\right)\)

\(PTHH:H_2SO_4+Ba\left(OH\right)_2\rightarrow BaSO_4+2H_2O\)

..................0,1............0,1...............0,1........................

Lại có : \(n_{Ba\left(OH\right)2}=0,45\left(mol\right)\)

=> Trong dung dịch B còn có Ba(OH)2 dư ( dư 0,45 - 0,3 - 0,1 = 0,05mol)

\(\Rightarrow C_{MBa\left(OH\right)2}=\dfrac{n}{V}=\dfrac{0,05}{0,5}=0,1\left(M\right)\)

Vậy ...

Châu Anh

\(PTHH:\)

\(CaO+2CH_3COOH--->(CH_3COO)_2Ca+H_2O\)

\(CaCO_3+2CH_3COOH--->(CH_3COO)_2Ca+CO_2+H_2O\)

\(a)\)

\(nCO_2=0,1(mol)\)

\(=>nCaCO_3=0,1(mol)\)

\(=>mCaCO_3=10(g)\)

\(\%mCaCO_3=\dfrac{10.100}{15,5}=64,52\%\)

\(=>\%mCaO=100\%-64,52\%=35,48\%\)

\(b)\)

\(mCaO=15,5-10=5,5(g)\)

\(=>nCaO=\dfrac{11}{112}\left(mol\right)\)

Theo PTHH (1) và (2) \(\sum nCH_3COOH=0,2+\dfrac{11}{56}=\dfrac{111}{280}\left(mol\right)\)

\(\Rightarrow mCH_3COOH=\dfrac{333}{14}\left(g\right)\)

\(C\%CH_3COOH=\dfrac{\dfrac{333}{14}}{200}.100=11.89\%\)

mình câu b cũng chưa tính ra

a. PTHH:

\(BaO+2HCl--->BaCl_2+H_2O\left(1\right)\)

\(BaCO_3+2HCl--->BaCl_2+CO_2\uparrow+H_2O\left(2\right)\)

Ta có: \(n_{CO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

Theo PT₍₂₎: \(n_{BaCO_3}=n_{CO_2}=0,2\left(mol\right)\)

\(\Rightarrow m_{BaCO_3}=0,2.197=39,4\left(g\right)\)

\(\Rightarrow\%_{m_{BaCO_3}}=\dfrac{39,4}{54,7}.100\%=72,03\%\)

\(\%_{m_{BaO}}=100\%-72,03\%=27,97\%\)

b. Ta có: \(m_{BaO}=54,7-39,4=15,3\left(g\right)\)

\(\Rightarrow n_{BaO}=\dfrac{15,3}{153}=0,1\left(mol\right)\)

\(\Rightarrow n_A=0,1+0,2=0,3\left(mol\right)\)

Theo PT_(1,2): \(n_{HCl}=2.n_A=2.0,3=0,6\left(mol\right)\)

\(\Rightarrow m_{HCl}=0,6.36,5=21,9\left(g\right)\)

Ta có: \(C_{\%_{HCl}}=\dfrac{21,9}{m_{dd_{HCl}}}.100\%=20\%\)

\(\Rightarrow m_{dd_{HCl}}=109,5\left(g\right)\)

\(n_{CO2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

a) Pt : \(BaO+2HCl\rightarrow BaCl_2+H_2O|\)

             1            2               1           1

            0,1        0,2

            \(BaCO_3+2HCl\rightarrow BaCl_2+CO_2+H_2O|\)

                  1             2             1            1          1

                 0,2         0,4                         0,2

\(n_{BaCO3}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)

\(m_{BaCO3}=0,2.197=39,4\left(g\right)\)

\(m_{BaO}=54,7-39,4=15,3\left(g\right)\)

⁰/₀BaO = \(\dfrac{15,3.100}{54,7}=27,97\)⁰/₀

⁰/₀BaCO₃ = \(\dfrac{39,4.100}{54,7}=72,03\)⁰/₀

b) Có : \(m_{BaO}=15,3\left(g\right)\)

\(n_{BaO}=\dfrac{15,3}{153}=0,1\left(mol\right)\)

\(n_{HCl\left(tổng\right)}=0,2+0,4=0,6\left(mol\right)\)

\(m_{HCl}=0,6.36,5=21,9\left(g\right)\)

\(m_{ddHCl}=\dfrac{21,9.100}{20}=109,5\left(g\right)\)

 Chúc bạn học tốt

             nCO2= 4,48 / 22.4= 0,2 ( mol)

a, BaO + 2HCl -> BaCl2 + H2O      (1)

BaCO3 + 2HCl-> BaCl2 + H2O + CO2   (2)

0,2                                                  <- 0,2       (mol)

Theo pt (2) ta có nBaCO3= 0,2 => mBaCO3= 0,2 x 197= 39,4 (g)

=> mBaO= 54,7- 39,4= 15.3 (g)

->% BaCO3= ( 39,4 : 54,7)x 100%= 72%

->% BaO= 100%-72% = 28%

Dễ mà bạn?
Áp dụng ĐLBTKL VÀ ĐLBTNT để tính nhé ^^

A