1.
nCO2=0,075mol

do dư KOH nên tạo ra muối trung hòa

nNa2CO3=nCO2=0,075mol

-->Cm=0,3M

2.
nCO2=0,5mol, nNaOH=4,0625mol

-->tạo muối Na2CO3 với số mol =nCO2=0,5mol

-->CmNa2CO3=1M

câu 1: nCO2=0,075mol

do dư KOH nên tạo ra muối trung hòa

nNa2CO3=nCO2=0,075mol

-->Cm=0,3M

câu 2:
nCO2=0,5mol, nNaOH=4,0625mol

-->tạo muối Na2CO3 với số mol =nCO2=0,5mol

-->CmNa2CO3=1M

câu 3: nCO2=0,02mol, nKOH=0,025mol

-->T=1,25 hay 1<T<2

tạo 2 muối

K2CO3:x, KHCO3:y

x+y=0,02
2x+y=0,025

-->x=0,005mol, y=0,015mol

-->mK2CO3=0,69g

mKHCO3=1,5g

Bài 1:

Ta có: \(n_{CO_2}=\dfrac{1,68}{22,4}=0,075\left(mol\right)\)

PTHH: CO₂ + 2KOH -> K₂CO₃ + H₂O

- Muối thu dc là K₂CO₃

\(n_{K_2CO_3}=n_{CO_2}=0,075\left(mol\right)\)

\(V_{ddK_2CO_3}=250\left(ml\right)=0,25\left(l\right)\)

=> \(C_{MddK_2CO_3}=\dfrac{0,075}{0,25}=0,3\left(M\right)\)

nCO2=0,075 mol

CO2 + 2KOH => K2CO3 + H2O
0,075 mol       =>0,075 mol
CM dd K2CO3=0,075/0,25=0,3M

cảm ơn chị

CO₂ + 2KOH → K₂CO₃ + H₂O

\(n_{CO_2}=\frac{1,68}{22,4}=0,075\left(mol\right)\)

Theo PT: \(n_{K_2CO_3}=n_{CO_2}=0,075\left(mol\right)\)

\(\Rightarrow C_{M_{K_2CO_3}}=\frac{0,075}{0,25}=0,3\left(M\right)\)

a) \(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\)

PTHH: 2Al + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂

           0,4-->0,6---------->0,2------->0,6

=> \(C_{M\left(dd.H_2SO_4\right)}=\dfrac{0,6}{0,15}=4M\)

b) V_H2 = 0,6.22,4 = 13,44 (l)

c) \(C_{M\left(Al_2\left(SO_4\right)_3\right)}=\dfrac{0,2}{0,15}=\dfrac{4}{3}M\)

\(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\\ pthh:2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\) 
           0,4     0,6                   0,2             0,6 
\(C_M_{H_2SO_4}=\dfrac{0,6}{0,15}=4M\\ V_{H_2}=0,622,4=13,44L\) 
\(C_M=\dfrac{0,2}{0,15}=1,3M\)

\(n_{CO_2}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)

\(m_{ddNaOH}=1,3.500=650\left(g\right)\)

\(\dfrac{m_{ctNaOH}.100\%}{650}=25\%\Rightarrow m_{ctNaOH}=162,5\left(g\right)\)

\(n_{NaOH}=\dfrac{162,5}{40}=4,0625\left(mol\right)\)=>NaOH dư

\(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)

0,5-----------------------0,5---------------

\(C_M=\dfrac{0,5}{0,5}=1M\)

Zn + 2HCl --> ZnCl2 + H2

0,5      1              0,5       0,5

nZn=\(\dfrac{32,5}{65}\)=0,5(mol)

mZnCl2=0,5.136=68(g)

VH2=0,5.22,4=11,2(l)

c) CM HCl=\(\dfrac{1}{0,25}=4M\)

c quá ghê gớm

PTHH: \(Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)

Ta có: \(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{HCl}=0,2\left(mol\right)\\n_{FeCl_2}=0,1\left(mol\right)=n_{H_2}\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{H_2}=0,1\cdot22,4=2,24\left(l\right)\\m_{FeCl_2}=0,1\cdot127=12,7\left(g\right)\\C_{M_{FeCl_2}}=\dfrac{0,1}{0,1}=1\left(M\right)\\C_{M_{HCl}}=\dfrac{0,2}{0,1}=2\left(M\right)\end{matrix}\right.\)