Tìm thể tích dung dịch KOH

- Phương trình hoá học :

H 2 SO 4  + 2KOH →  K 2 SO 4  + 2 H 2 O

- Số mol KOH tham gia phản ứng :

n KOH = 2 n H 2 SO 4  = 0,02 x 2 = 0,04 mol

- Khối lượng KOH tham gia phản ứng : mKOH = 0,04 x 56 = 2,24 (gam).

- Khối lượng dung dịch KOH cần dùng :

m dd   KOH  = 2,24x100/5,6 = 40 gam

- Thể tích dung dịch KOH cần dùng:

V dd   KOH  = 40/1,045 ≈ 38,278 ml

nH2SO4=0,02.1=0,02(ol)

a) PTHH: 2 NaOH + H2SO4 -> Na2SO4 + 2 H2O

0,04____________0,02____0,02(mol)

mNaOH=0,04.40= 1,6(g)

=>mddNaOH= (1,6.100)/20= 8(g)

b) PTHH: H2SO4 + 2 KOH -> K2SO4 + 2 H2O

0,2____________0,04(mol)

=>mKOH=0,04.56=2,24(g)

=>mddKOH= (2,24.100)/5,6=40(g)

=>VddKOH= mddKOH/DddKOH= 40/1,045=38,278(ml)

\(n_{H_2SO_4}=0.02\cdot1=0.02\left(mol\right)\)

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

\(0.04........0.02\)

\(m_{KOH}=0.04\cdot56=2.24\left(g\right)\)

\(V_{dd_{KOH}}=\dfrac{2.24}{5.6\%\cdot1.045}=38.27\left(ml\right)\)

\(n_{H_2SO_4}=1.0,2=0,2(mol)\\ PTHH:2NaOH+H_2SO_4\to Na_2SO_4+2H_2O\\ a,n_{NaOH}=0,4(mol);n_{Na_2SO_4}=0,2(mol)\\ \Rightarrow \begin{cases} m_{Na_2SO_4}=0,2.142=28,4(g)\\ m_{dd_{NaOH}}=\dfrac{0,4.40}{20\%}=80(g) \end{cases}\\ b,2KOH+H_2SO_4\to K_2SO_4+2H_2O\\ \Rightarrow n_{KOH}=0,4(mol)\\ \Rightarrow m_{dd_{KOH}}=\dfrac{0,4.56}{5,6\%}=400(g)\\ \Rightarrow V_{dd_{KOH}}=\dfrac{400}{1,045}=382,78(ml)\)

Bước 1: nH2SO4 = VH2SO4 . CM H2SO4= 0,2 . 1 = 0,2mol

Bước 2:

PTHH:       2NaOH    +    H2SO4 →  Na2SO4 + H2O

                     2 mol             1 mol     

                    ? mol               0,2mol

a) $2NaOH + H_2SO_4 \to Na_2SO_4 + 2H_2O$

b)

n H2SO4 = 0,03.1 = 0,03(mol)

n NaOH = 2n H2SO4 = 0,06(mol)

=> CM NaOH = 0,06/0,05 = 1,2M

c) $H_2SO_4 + 2KOH \to K_2SO_4 + 2H_2O$

n KOH = 2n H2SO4 = 0,06(mol)

=> m KOH = 0,06.56 = 3,36 gam

=> m dd KOH = 3,36/5,6% = 60(gam)

=> V dd KOH = m/D = 60/1,045 = 57,42(ml)

a) PTHH : H₂SO₄ + 2KOH ----> K₂SO₄ + 2H₂O

b) n_H2SO4 = 0,2 . 1 = 0,2(mol)

Theo pthh : n_KOH = 2n_h2so4 = 0,4 (mol)

--> m_KOH = 0,4.56 = 22,4 (g)

---> m_(ddKOH)  = 22,4 : 6 . 100 = 373,33 (g)

---> V_(ddKOH) = 373,33 : 1,048 = 356,23 (ml)

p/s: check lại hộ mình phát =)))

a,b)\(n_{H_2SO_4}=0,2\) theo PT \(2n_{H_2SO_4}=n_{NaOV}=0,4\Rightarrow m_{NaOV}=0,4.4016kg\)

                        \(H_2SO_4+2NaOH\rightarrow H_2Na_2SO_4+H_2\)

\(m_{ddNaOH}=\dfrac{16}{2}=80g\)

c)\(n_{KOH}=2_{n_{H_2SO_4}}=0,4\Rightarrow m_{KOH}=0,3.56-22,4g\)

\(\Rightarrow m_{KOH\left(dd\right)}=\dfrac{22,4}{0,056}=400\Rightarrow V=\dfrac{400}{1,045}=182,8\left(ml\right)\)

a, \(H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\)    \(\left(1\right)\)

b, Đổi \(20ml=0,02l\)

\(n_{H_2SO_4}=0,02.1=0,02\left(mol\right)\)

Thep phương trình \(\left(1\right)\) ta được:

\(n_{NaOH}=2n_{H_2SO_4}=2.0,02=0,04\left(mol\right)\\ \Rightarrow m_{NaOH}=0,04.40=1,6\left(g\right)\\ \Rightarrow m_{dd NaOH}=\dfrac{1,6}{20}.100=8\left(g\right)\)

c, \(H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O\)    \(\left(2\right)\)

Theo phương trình \(\left(2\right)\):

\(n_{KOH}=2n_{H_2SO_4}=2.0,02=0,04\left(mol\right)\\ \Rightarrow m_{KOH}=0,04.56=2,24\left(g\right)\\ \Rightarrow m_{dd KOH}=\dfrac{2,24}{5,6}.100=40\left(g\right)\\ \Rightarrow V_{dd KOH}=\dfrac{40}{1.045}=38,3\left(ml\right)\)

Dd HCl có CM không bạn?

Câu 7 : 

\(n_{H2SO4}=0,1.1=0,1\left(mol\right)\)

Pt : \(H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\)

\(n_{NaOH}=2n_{H2SO4}=2.0,1=0,2\left(mol\right)\Rightarrow V_{ddNaOH}=\dfrac{0,2}{1}=0,2\left(l\right)=200\left(ml\right)\)

Câu 8 : 

\(n_{H2SO4}=0,5.0,7=0,35\left(mol\right)\)

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

\(n_{KOH}=2n_{H2SO4}=2.0,35=0,7\left(mol\right)\)

\(\Rightarrow m_{ddKOH}=\dfrac{0,7.56}{12\%}.100\%=326,67\left(g\right)\)

\(\Rightarrow V_{ddKOH}=\dfrac{326,67}{1,15}=284,06\left(ml\right)\)

Câu 12 : 

a) \(2Cu+O_2\xrightarrow[]{t^o}2CuO\)

 \(CuO+2HCl\rightarrow CuCl_2+H_2O\)

\(CuCl_2+2NaOH\rightarrow Cu\left(OH\right)_2+2NaCl\)

\(Cu\left(OH\right)_2\xrightarrow[]{t^o}CuO+H_2O\)

\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)

\(CuSO_4+Fe\rightarrow FeSO_4+Cu\downarrow\)

b) \(MgSO_4+2KOH\rightarrow Mg\left(OH\right)_2+K_2SO_4\)

\(Mg\left(OH\right)_2\xrightarrow[]{t^o}MgO+H_2O\)

\(MgO+2HCl\rightarrow MgCl_2+H_2O\)

\(MgCl_2+2AgNO_3\rightarrow Mg\left(NO_3\right)_2+2AgCl\)

\(Mg\left(NO_3\right)_2+Na_2CO_3\rightarrow MgCO_3+2NaNO_3\)

\(MgCO_3\xrightarrow[]{t^o}MgO+CO_2\)

c) \(2Na+2H_2O\rightarrow2NaOH+H_2\)

\(NaOH=HCl\rightarrow NaCl+H_2O\)

\(2NaCl+2H_2O\xrightarrow[cmn]{đpdd}2NaOH+H_2+Cl_2\)

\(Cl_2+H_2\xrightarrow[]{as}2HCl\)

\(HCl+Fe\rightarrow FeCl_2+H_2\)

\(FeCl_2+2NaOH\rightarrow Fe\left(OH\right)_2+2NaCl\)

\(Fe\left(OH\right)_2+H_2SO_4\rightarrow FeSO_4+2H_2O\)

\(FeSO_4+BaCl_2\rightarrow FeCl_2+BaSO_4\)

\(FeCl_2+2AgNO_3\rightarrow Fe\left(NO_3\right)_2+2AgCl\)

\(Fe\left(NO_3\right)_2+Mg\rightarrow Mg\left(NO_3\right)_2+Fe\)

e) \(4Al+3O_2\xrightarrow[]{t^o}2Al_2O_3\)

\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)

\(Al_2\left(SO_4\right)_3+6KOH\rightarrow2Al\left(OH\right)_3+3K_2SO_4\)

\(Al\left(OH\right)_3+3HNO_3\rightarrow Al\left(NO_3\right)_3+3H_2O\)

\(Al\left(NO_3\right)_2+Mg\rightarrow Mg\left(NO_3\right)_2+Âl\)

\(2Al+3Cl_2\xrightarrow[]{t^o}2AlCl_3\)

Bạn xem đề chỗ AlCl₃ ra Al₂(SO₄)₃ nhé

Câu 10 : 

\(n_{KOH}=\dfrac{5,6\%.400}{100\%.56}=0,4\left(mol\right)\)

\(n_{CuSO4}=\dfrac{16\%.300}{100\%.160}=0,3\left(mol\right)\)

Pt : \(2KOH+CuSO_4\rightarrow K_2SO_4+Cu\left(OH\right)_2\)

         0,4          0,3                                0,2

Xét tỉ lệ : \(\dfrac{0,4}{2}< \dfrac{0,3}{1}\Rightarrow CuSO_4dư\)

\(\Rightarrow m_{kt}=m_{Cu\left(OH\right)2}=0,2.98=19,6\left(g\right)\)

Câu 11 : 

\(n_{BaCl2}=0,1.1=0,1\left(mol\right)\)

Pt : \(BaCl_2+K_2CO_3\rightarrow BaCO_3+2KCl\)

\(n_{KCl}=2n_{BaCl2}=2.0,1=0,2\left(mol\right)\Rightarrow C_{MKCl}=\dfrac{0,2}{0,1+0,1}=1M\)