\(n_{KOH}=0.4\cdot2=0.8\left(mol\right)\)

\(2KOH+H_2SO_4\rightarrow K_2SO_4+H_2O\)

\(0.8..............0.4............0.4\)

\(V_{dd_{H_2SO_4}}=\dfrac{0.4}{0.5}=0.8\left(l\right)\)

\(C_{M_{K_2SO_4}}=\dfrac{0.4}{0.4+0.8}=0.33\left(M\right)\)

\(2KOH+H2SO4\rightarrow K2SO4+2H2O\)

\(n_{KOH}=0,4.2=0,8\left(mol\right)\)

Theo PT:

\(n_{H2SO4}=n_{K2SO4}=\dfrac{1}{2}n_{KOH}=0,4\left(mol\right)\)

\(\Rightarrow V_{H2SO4}=\dfrac{0,4}{0,5}=0,8\left(l\right)\)

\(V_{dd}saupư_{K2SO4}=0,4+0,8=1,2\left(l\right)\)

\(C_{M\left(K2SO4\right)}=\dfrac{0,4}{1,2}=\dfrac{1}{3}\left(M\right)\)

a) \(n_{NaOH}=0,2.1=0,2\left(mol\right);n_{H_2SO_4}=0,15.2=0,3\left(mol\right)\)

PTHH: 2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

Mol:         0,2                            0,1

Ta có: \(\dfrac{0,2}{2}< \dfrac{0,3}{1}\) ⇒ NaOH hết, H₂SO₄ dư

\(m_{Na_2SO_4}=0,1.142=14,2\left(g\right)\)

b) V_{dd sau pứ} = 0,2 + 0,15 = 0,35 (l)

\(C_{M_{ddNa_2SO_4}}=\dfrac{0,1}{0,35}=\dfrac{2}{7}\approx0,2857M\)

\(C_{M_{ddH_2SO_4dư}}=\dfrac{0,3-0,1}{0,35}=\dfrac{4}{7}\approx0,57M\)

PTHH: \(H_2SO_4+Ba\left(NO_3\right)_2\rightarrow2HNO_3+BaSO_4\downarrow\)

Ta có: \(\left\{{}\begin{matrix}n_{H_2SO_4}=0,1\cdot2=0,2\left(mol\right)\\n_{Ba\left(NO_3\right)_2}=0,1\cdot1=0,1\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\) H₂SO₄ còn dư

\(\Rightarrow\left\{{}\begin{matrix}n_{HNO_3}=0,2\left(mol\right)\\n_{H_2SO_4\left(dư\right)}=0,1\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}C_{M_{HNO_3}}=\dfrac{0,2}{0,2}=1\left(M\right)\\C_{M_{H_2SO_4\left(dư\right)}}=\dfrac{0,1}{0,2}=0,5\left(M\right)\end{matrix}\right.\)

PTHH: \(CaCl_2+Na_2CO_3\rightarrow CaCO_3\downarrow+2NaCl\)

a+b) Ta có: \(n_{CaCl_2}=0,1\cdot2=0,2\left(mol\right)\) 

\(\Rightarrow\left\{{}\begin{matrix}n_{CaCO_3}=0,2\left(mol\right)\\n_{NaCl}=0,4\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{CaCO_3}=0,2\cdot100=20\left(g\right)\\C_{M_{NaCl}}=\dfrac{0,4}{0,1+0,2}\approx1,33\left(M\right)\end{matrix}\right.\)

c) PTHH: \(CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2\)

Theo PTHH: \(n_{HCl}=2n_{CaCO_3}=0,4\left(mol\right)\) \(\Rightarrow m_{ddHCl}=\dfrac{0,4\cdot36,5}{10\%}=146\left(g\right)\)

a.PTHH:CaCl2+Na2CO3--->CaCO3+2NaCl

Ta có:nCaCl2=0,2

=>nCaCO3=nCaCl2=0,2(mol)=>mCaCO3(kết tủa)=100.0,2=2(g)

b.Vdd=100+200=300(ml)=0,3(l)

CM Nacl=(2.0,2)/0,3=4/3(M)(Đề cho 2 chất td vừa đủ nên dd sau pứ chỉ có NaCl)

c.CaCO3+2HCl--->CaCl2+CO2+H2O

nHCl(cần dùng)=2.0.2=0,4(mol)=>mHCl=36,5.0,4=14,6(g)

=>mddHCl=14,6/10%=146(g)

n_NaOH = 0,1.2 = 0,2 (mol)

PTHH: CH₃COOH + NaOH --> CH₃COONa + H₂O

                0,2<--------0,2

=> \(C_{M\left(dd.CH_3COOH\right)}=\dfrac{0,2}{0,15}=\dfrac{4}{3}M\)

nNaOH = 0,1 . 2 = 0,2 (mol)

PTHH: CH3COOH + NaOH -> CH3COONa + H2O

nCH3COOH = nNaOH = 0,2 (mol)

CM(CH3COOH) = 0,2/0,15 = 1,33M

\(n_{NaOH}=0.2\cdot0.5=0.1\left(mol\right)\)

\(n_{CuSO_4}=0.1\cdot2=0.2\left(mol\right)\)

\(2NaOH+CuSO_4\rightarrow Na_2SO_4+Cu\left(OH\right)_2\)

\(0.1.............0.05...............0.05...........0.05\)

\(m_{Cu\left(OH\right)_2}=0.05\cdot98=4.9\left(g\right)\)

\(C_{M_{Na_2SO_4}}=\dfrac{0.05}{0.2+0.1}=0.167\left(M\right)\)

\(C_{M_{CuSO_4\left(dư\right)}}=\dfrac{0.2-0.05}{0.1}=1.5\left(M\right)\)

a,Gọi nHCl là a, nH2SO4 là b

mddNaOH = 400×1,2 = 480(g)

mNaOH = (480×5)/100 = 24 (g)

nNaOH = 24/40 = 0,6(mol)

HCl + NaOH-> NaCl + H2O (1)

 a   ->  a                            (mol) 

H2SO4 + 2NaOH-> Na2SO4 +

b     ->      2b                 (mol)     

2H2O (2)

Ta có : a + 2b= 0,6 

Mà a:b = 1 => a=b, thay a vào phương trình trên ta được 

a + 2a = 0,6 <=> 3a = 0,6 

=> a = b = 0,6/3 = 0,2 (mol)

CMHCl = 0,2/0,1 = 2M

CMH2SO4 = 0,2/0,1 = 2M

b, Theo (1) và (2) ta có : 

nNaCl = nHCl = 0,2 (mol)

nNa2SO4 = nH2SO4 = 0,2 (mol)

Tổng khối lượng muối thu được sau khi cô cạn là: 

m= mNaCl + mNa2SO4 = 0,2×58,5 + 0,2×142= 40,1(g)