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)

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

a. PTPỨ:  H₂SO₄ +  2NaOH \(\rightarrow\)  2H₂O +  Na₂SO₄

b. Ta có : n_H2SO4 = \(\frac{1.20}{1000}\) = 0,02 mol

c. Theo phương trình: n_NaOH = 2.n_H2SO4 = 2.0,02 = 0,04 mol

\(\Rightarrow\) m_NaOH = 0,04. 40 = 1,6(g)

d. m_{dd NaOH} = \(\frac{1,6.100}{20}\) = 8(g)

e₁.  PTHH: H₂SO₄ + 2KOH \(\rightarrow\)  K₂SO₄ + 2H₂O

Ta có: n_KOH = 2. n_H2SO4 = 2. 0,02 = 0,04 mol

\(\Rightarrow\) m_KOH = 0,04.56=2,24(g)

e₂. m_{dd KOH} = \(\frac{2,24.100}{5,6}\) = 40(g)

e₃. V_{dd KOH} = \(\frac{40}{1,045}\) \(\approx\) 38,278 ml

a)$n_{H_2SO_4} = 0,3.1,5 = 0,45(mol)$

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

$n_{NaOH} = 2n_{H_2SO_4} = 0,9(mol)$
$m_{dd\ NaOH} = \dfrac{0,9.40}{40\%} = 90(gam)$

b)

$n_{KOH} = n_{NaOH} = 0,9(mol0$
$m_{dd\ KOH} = \dfrac{0,9.56}{5,6\%} = 900(gam)$
$V_{dd\ KOH} = \dfrac{m}{D} = \dfrac{900}{1,045} = 861,24(ml)$

\(n_{H_2SO_4}=C_M.V=0,2.1=0,2\left(mol\right)\)

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

(mol) 1 2 1 2

(mol) 0,2 0,4 0,2 0,4

\(a.m_{NaOH}=n.M=0,4.40=16\left(g\right)\\ \rightarrow m_{ddNaOH}=\frac{16.100}{20}=80\left(g\right)\)

\(b.\\ PTHH:2KOH+H_2SO_4\rightarrow K_2SO_4+2H_2O\)

(mol) 2 1 1 2

(mol) 0,4 0,2 0,2 0,4

\(m_{KOH}=n.M=0,4.56=22,4\left(g\right)\\ \rightarrow m_{ddKOH}=\frac{22,4.100}{5,6}=400\left(g\right)\\ \rightarrow V_{ddKOH}=\frac{m}{D}=\frac{400}{1,045}=382,77\left(ml\right)=0,382\left(l\right)\)

a) Đổi 20ml = 0,02 (l)

Ta có công thức:

CM = n.V

=> n_{\(H_2SO_4\)} = C_M . V

<=> 1 . 0,02 = 0,02 (mol)

PTHH: 2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

PTPT: 2 mol 1mol

PTĐB: x(mol) 0,02mol

n_NaOH=\(\frac{2.0.02}{1}\)= 0,04 (mol)

-> m_NaOH= n . M = 0,04 . 40 = 1,6 (g)
-> m_ddNaOH=\(1,6.\frac{100\%}{20\%}=8\left(g\right)\)

\(a,n_{H_2SO_4}=1.0,1=0,1(mol)\\ PTHH:2NaOH+H_2SO_4\to Na_2SO_4+2H_2O\\ \Rightarrow n_{naOH}=2n_{H_2SO_4}=0,2(mol)\\ \Rightarrow m_{dd_{NaOH}}=\dfrac{0,2.40}{10\%}=80(g)\\ b,m_{dd_{H_2SO_4}}=1,2.100=120(g)\\ n_{Na_2SO_4}=0,1(mol)\\ \Rightarrow C\%_{Na_2SO_4}=\dfrac{0,1.142}{80+120}.100\%=7,1\%\)

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

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

\(n_{NaOH}=0.1\cdot0.1=0.01\left(mol\right)\)

\(n_{KOH}=0.1\cdot0.1=0.01\left(mol\right)\)

\(V=0.1+0.1=0.2\left(l\right)\)

\(\left[Na^+\right]=\dfrac{0.01}{0.2}=0.05\left(M\right)\)

\(\left[K^+\right]=\dfrac{0.01}{0.2}=0.05\left(M\right)\)

\(\left[OH^-\right]=\dfrac{0.01+0.01}{0.2}=0.1\left(M\right)\)

\(b.\)

\(pH=14+log\left[OH^-\right]=14+log\left(0.1\right)=13\)

\(c.\)

\(H^++OH^-\rightarrow H_2O\)

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

\(V_{dd_{H_2SO_4}}=\dfrac{0.02}{1}=0.02\left(l\right)\)

\(a.\)

\(n_{NaOH}=0.1\cdot0.1=0.01\left(mol\right)\)

\(n_{KOH}=0.1\cdot0.1=0.01\left(mol\right)\)

\(V=0.1+0.1=0.2\left(l\right)\)

\(\left[Na^+\right]=\dfrac{0.01}{0.2}=0.05\left(M\right)\)

\(\left[K^+\right]=\dfrac{0.01}{0.2}=0.05\left(M\right)\)

\(\left[OH^+\right]=\dfrac{0.01+0.01}{0.2}=0.1\left(M\right)\)

\(b.\)

\(pH=14+log\left(0.1\right)=13\)

\(c.\)

\(H^++OH^-\rightarrow H_2O\)

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

\(V_{H_2SO_4}=\dfrac{0.02}{1}=0.02\left(l\right)\)

a) Ta có: \(n_{NaOH}=0,1\cdot0,1=n_{KOH}=0,01\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{OH^-}=0,02\left(mol\right)\\n_{Na^+}=n_{K^+}=0,01\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}\left[OH^-\right]=\dfrac{0,02}{0,2}=0,1\left(M\right)\\\left[Na^+\right]=\left[K^+\right]=\dfrac{0,01}{0,2}=0,05\left(M\right)\end{matrix}\right.\)

b) Ta có: \(pH=14+log\left[OH^-\right]=13\)

c) PT ion: \(OH^-+H^+\rightarrow H_2O\)

Theo PT ion: \(n_{H^+}=n_{OH^-}=0,02\left(mol\right)\)

\(\Rightarrow n_{H_2SO_4}=0,01\left(mol\right)\) \(\Rightarrow V_{ddH_2SO_4}=\dfrac{0,01}{1}=0,01\left(l\right)=10\left(ml\right)\)