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a, \(Na_2O+H_2O\rightarrow2NaOH\)
Ta có: \(n_{Na_2O}=\dfrac{15,5}{62}=0,25\left(mol\right)\)
Theo PT: \(n_{NaOH}=2n_{Na_2O}=0,5\left(mol\right)\)
\(\Rightarrow CM_{NaOH}=\dfrac{0,5}{0,5}=1\left(M\right)\)
b, \(2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\)
Theo PT: \(n_{H_2SO_4}=\dfrac{1}{2}n_{NaOH}=0,25\left(mol\right)\)
\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,25.98}{20\%}=122,5\left(g\right)\)
\(\Rightarrow V_{ddH_2SO_4}=\dfrac{122,5}{1,14}\approx107,46\left(ml\right)\)
a, \(Na_2O+H_2O\rightarrow2NaOH\)
\(n_{Na_2O}=\dfrac{15,5}{62}=0,25\left(mol\right)\)
\(n_{NaOH}=2n_{Na_2O}=0,5\left(mol\right)\)
\(\Rightarrow C_{M_{NaOH}}=\dfrac{0,5}{0,5}=1\left(M\right)\)
b, \(H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\)
\(n_{H_2SO_4}=\dfrac{1}{2}n_{NaOH}=0,25\left(mol\right)\)
\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,25.98}{20\%}=122,5\left(g\right)\)
\(\Rightarrow V_{ddH_2SO_4}=\dfrac{122,5}{1,14}\approx107,46\left(ml\right)\)
a)
\(n_{Na_2O}=\dfrac{31}{62}=0,5\left(mol\right)\)
PTHH: Na2O + H2O --> 2NaOH
______0,5--------------->1
=> \(C_{M\left(NaOH\right)}=\dfrac{1}{0,5}=2M\)
b)
PTHH: H2SO4 + 2NaOH --> Na2SO4 + 2H2O
______0,5<---------1
=> mH2SO4 = 0,5.98 = 49(g)
=> \(m_{dd\left(H_2SO_4\right)}=\dfrac{49.100}{20}=245\left(g\right)\)
=> \(V_{dd\left(H_2SO_4\right)}=\dfrac{245}{1,14}=214,912\left(ml\right)\)
\(n_{Na_2O}=\dfrac{31}{62}=0,5(mol)\\ a,Na_2O+H_2O\to 2NaOH\\ \Rightarrow n_{NaOH}=1(mol)\\ \Rightarrow C_{M_{NaOH}}=\dfrac{1}{0,5}=2M\\ b,2NaOH+H_2SO_4\to Na_2SO_4+2H_2O\\ \Rightarrow n_{H_2SO_4}=0,5(mol)\\ \Rightarrow m_{dd_{H_2SO_4}}=\dfrac{0,5.98}{20\%}=245(g)\\ \Rightarrow V_{dd_{H_2SO_4}}=\dfrac{245}{1,14}=214,91(ml)\)
\(n_{Na_2O}=\dfrac{15.5}{62}=0.25\left(mol\right)\)
\(Na_2O+H_2O\rightarrow2NaOH\)
\(0.25.......................0.5\)
\(C_{M_{NaOH}}=\dfrac{0.5}{0.5}=1\left(M\right)\)
b.
\(2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\)
\(0.5..............0.25\)
\(V_{dd_{H_2SO_4}}=\dfrac{0.25}{2}=0.125\left(l\right)\)
\(a.n_{Na_2O}=\dfrac{15,5}{62}=0,25\left(mol\right)\\ PTHH:Na_2O+H_2O\rightarrow2NaOH\\ 0,25...................................0,5\left(mol\right)\\ C_{MddNaOH}=\dfrac{0,5}{0,5}=1\left(M\right)\\ b.H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\\ 0,25............0,5..........0,25\left(mol\right)\\ V_{ddH_2SO_4}=\dfrac{0,25}{2}=0,125\left(l\right)\)
a)
$Na_2O + H_2O \to 2NaOH$
n Na2O = 15,5/62 = 0,25(mol)
n NaOH = 2n Na2O = 0,5(mol)
=> CM NaOH = 0,5/0,5 = 1M
b) $2NaOH + H_2SO_4 \to Na_2SO_4 + 2H_2O$
n H2SO4 = 1/2 n NaOH = 0,25(mol)
=> m dd H2SO4 = 0,25.98/20% = 122,5(gam)
=> V dd H2SO4 = m / D = 122,5/1,14 =107,46(ml)
c) n Na2SO4 = n H2SO4 = 0,25(mol)
CM Na2SO4 = 0,25/0,10746 = 2,33M
a)
`\(Na_2O++H_{2_{ }}O->2NaOH\)
\(n_{Na_2O}=\dfrac{15,5}{62}=0,25mol\)
\(n_{Na_2O}=2n_{Na_2O}=0,5mol\)
\(C_{M_{NaOH}}=\dfrac{0,5}{0,5}\)=1M
nK2O = \(\dfrac{23,5}{94}=0,25\left(mol\right)\)
Pt: K2O + H2O --> 2KOH
.....0,25 mol-------> 0,5 mol
CM KOH = \(\dfrac{0,5}{0,5}=1\left(M\right)\)
b) Pt: 2KOH + H2SO4 --> K2SO4 + 2H2O
..........0,5 mol->0,25 mol
mdd H2SO4 cần = \(\dfrac{0,25.98}{20}.100=122,5\left(g\right)\)
c) nCuCl2 = 1 . 0,1 = 0,1 mol
Pt: CuCl2 + 2NaOH --> Cu(OH)2 + 2NaCl
.....0,1 mol---------------> 0,1 mol
Xét tỉ lệ mol giữa CuCl2 và NaOH:
\(\dfrac{0,1}{1}< \dfrac{0,5}{2}\)
Vậy NaOH dư
mCu(OH)2 thu được = 0,1 . 98 = 9,8 (g)
nNa2O=0.1(mol)
pthh:Na2O+H2O->2NaOH
theo pthh:nH2O=nNa2O->nH2O=0.1(mol)->mH2O=0.1*18=1.8(g)
b)Theo pthh:nNaOH=2 nNa2O
->nNaOH=0.1*2=0.2(mol)
CM=0.2:0.2=1(M)
Khk bt là gì bạn? =)) câu b mình không tìm thấy lỗi sai.bạn chỉ cho mình với?