Câu 1:

PTHH: \(NaOH+HCl\rightarrow NaCl+H_2O\)

Ta có: \(n_{HCl}=0,2\cdot2=0,4\left(mol\right)=n_{NaOH}\)

\(\Rightarrow C_{M_{NaOH}}=\dfrac{0,4}{0,2}=2\left(M\right)\)

Câu 2: Bạn xem lại đề !!

Chỗ 6g là số gam ạ!

Tại em đọc nhanh nên máy viết sai 

Bài 1:

\(a.n_{NaOH\left(tổng\right)}=0,05.1+0,2.0,2=0,09\left(mol\right)\\ V_{ddNaOH\left(tổng\right)}=50+200=250\left(ml\right)=0,25\left(l\right)\\ C_{MddNaOH\left(cuối\right)}=\dfrac{0,09}{0,25}=0,36\left(M\right)\\ b.n_{HCl}=0,5.0,02=0,01\left(mol\right)\\ n_{H_2SO_4}=0,08.0,2=0,016\left(mol\right)\\ V_{ddsau}=20+80=100\left(ml\right)=0,1\left(l\right)\\ C_{MddH_2SO_4}=\dfrac{0,016}{0,1}=0,16\left(M\right)\\ C_{MddHCl}=\dfrac{0,01}{0,1}=0,1\left(M\right)\)

Bài 2:

\(a.m_{H_2SO_4}=29,4.10\%=2,94\left(g\right)\\ b.n_{H_2SO_4}=\dfrac{2,94}{98}=0,03\left(mol\right)\\ n_{Fe}=\dfrac{0,56}{56}=0,01\left(mol\right)\\ Fe+H_2SO_4\rightarrow FeSO_4+H_2\\ Vì:\dfrac{0,01}{1}< \dfrac{0,03}{1}\Rightarrow H_2SO_4dư\\ n_{H_2SO_4\left(dư\right)}=0,03-0,01=0,02\left(mol\right)\\ m_{H_2SO_4\left(dư\right)}=0,02.98=1,96\left(g\right)\\ n_{H_2}=n_{Fe}=0,01\left(mol\right)\\ \Rightarrow V_{H_2\left(đktc\right)}=0,01.22,4=0,224\left(l\right)\)

chăm chỉ

Bài 1:

n_{H2SO4 bđ} = 0,5 . 0,2 = 0,1 mol

n_H2 = \(\dfrac{1,792}{22,4}=0,08\left(mol\right)\)

Pt: Zn + H₂SO₄ --> ZnSO₄ + H₂

............0,08 mol<-0,08 mol<-0,08 mol

Theo pt: n_{H2SO4 pứ} = n_H2 = 0,08 mol < 0,1 mol

=> HCl dư

C_{M H2SO4 dư} = \(\dfrac{\left(0,1-0,08\right)}{0,2}=0,1M\)

C_{M ZnSO4} = \(\dfrac{0,08}{0,2}=0,4M\)

Bài 2:

n_CuO = \(\dfrac{3,2}{80}=0,04\left(mol\right)\)

m_H2SO4 = \(\dfrac{150\times32,666}{100}=49\left(g\right)\)

n_H2SO4 = \(\dfrac{49}{98}=0,5\left(mol\right)\)

Pt: CuO + H₂SO₄ --> CuSO₄ + H₂O

0,04 mol->0,04 mol->0,04 mol

Xét tỉ lệ mol giữa CuO và H2SO4:

\(\dfrac{0,04}{1}< \dfrac{0,5}{1}\)

Vậy H2SO4 dư

m_{H2SO4 dư} = (0,5 - 0,04) . 98 = 45,08 (g)

m_CuSO4 = 0,04 . 160 = 6,4 (g)

mdd sau pứ = mCuO + mdd H2SO4 = 3,2 + 150 = 153,2 (g)

C% dd CuSO4 = \(\dfrac{6,4}{153,2}.100\%=4,177\%\)

C% dd H2SO4 dư = \(\dfrac{45,08}{153,2}.100\%=29,425\%\)

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câu 1 
\(n_{Fe}=\dfrac{14}{56}=0,25\left(mol\right)\\ pthh:Fe+2HCl\rightarrow FeCl_2+H_2\) 
           0,25   0,5         0,25       0,25 
\(m_{FeCl_2}=0,25.127=31,75g\\ V_{H_2}=0,25.22,4=5,6\\ C_{M\left(HCl\right)}=\dfrac{0,5}{0,2}=2,5M\)
câu 2 
1 ) \(m_{\text{dd}}=35+100=135g\\ 2,C\%=\dfrac{204}{204+100}.100=60\%\\ =>m\text{dd}=\dfrac{100.204}{60}=340g\)
 

a)

C% CuSO4 = 16/(16 + 184)  .100% = 8%
b)

n NaOH = 20/40 = 0,5(mol)

CM NaOH = 0,5/4 = 0,125M

\(a.\)

\(m_{dd_{CuSO_4\:}}=16+184=200\left(g\right)\)

\(C\%_{CuSO_4}=\dfrac{16}{200}\cdot100\%=8\%\)

\(b.\)

\(n_{NaOH}=\dfrac{20}{40}=0.5\left(mol\right)\)

\(C_{M_{NaOH}}=\dfrac{0.5}{4}=0.125\left(M\right)\)

\(a.Fe+2HCl\rightarrow FeCl_2+H_2\\ b.n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\\ TheoPT:n_{HCl}=2n_{Fe}=0,2\left(mol\right)\\ \Rightarrow CM_{HCl}=\dfrac{0,2}{0,2}=1M\)