Câu 30: Trung hòa 100ml dd HCl 1M bằng dd KOH 20%. Khối lượng dung dịch KOH cần dùng là ?
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![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
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)
![](https://rs.olm.vn/images/avt/0.png?1311)
nH2SO4=0,1(mol)
a) PTHH: 2 NaOH + H2SO4 -> Na2SO4 + 2 H2O
b) 0,2___________0,1________0,1(mol)
mNaOH=0,2.40=8(g)
=>mddNaOH=(8.100)/25= 32(g)
c) mNa2SO4=0,1.142=14,2(g)
d) PTHH: 2 KOH + H2SO4 -> K2SO4 +2 H2O
nKOH=0,2(mol) => mKOH=0,2.56=11,2(g)
=> mddKOH=(11,2.100)/8=140(g)
=> VddKOH= 140/1,085=129,03(ml)
Chúc em học tốt!
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{H_2SO_4}=0,1.0,75=0,075mol\\ H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O\)
0,075 0,15 0,075 0,15
\(a)m_{K_2SO_4}=0,075.175=13,05mol\)
\(b)H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\\ n_{NaOH}=0,075.2=0,15mol\\ m_{ddNaOH}=\dfrac{0,15.40}{15\%}\cdot100\%=40g\\ V_{ddNaOH}=\dfrac{40}{1,05}=38,1ml\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Đổi 100ml = 0,1 lít
Ta có: \(C_{M_{KOH}}=\dfrac{n_{KOH}}{0,1}=0,5M\)
=> \(n_{KOH}=0,05\left(mol\right)\)
a. PTHH: 2KOH + H2SO4 ---> K2SO4 + 2H2O
b. Theo PT: \(n_{H_2SO_4}=\dfrac{1}{2}.n_{KOH}=\dfrac{1}{2}.0,05=0,025\left(mol\right)\)
Vì H2SO4 là chất lỏng nên thể tích bằng số mol của chính nó.
c. PTHH: KOH + HCl ---> KCl + H2O
Theo PT: \(n_{HCl}=n_{KOH}=0,05\left(mol\right)\)
=> \(m_{HCl}=0,05.36,5=1,825\left(g\right)\)
Ta có; \(C_{\%_{HCl}}=\dfrac{1,825}{m_{dd_{HCl}}}.100\%=20\%\)
=> \(m_{dd_{HCl}}=9,125\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a.250ml=0,25l ; nHCl=0,25.1,5=0,375mol
KOH+HCl->KCl+H2O
1mol 1mol 1mol
0,375 0,375 0,375
VKOh=0,375/2=0,1875l
b.CM KCL=0,375/0,25=1,5M
c.NaOH+HCL=NaCl+H2O
1mol 1mol
0,375 0,375
mdd NaOH=0,375.40.100/10=150g
![](https://rs.olm.vn/images/avt/0.png?1311)
a) \(2KOH+H_2SO_4\rightarrow K_2SO_4+2H_2O\)
\(n_{KOH}=\dfrac{200.11,2\%}{56}=0,4\left(mol\right)\)
\(n_{H_2SO_4}=\dfrac{1}{2}n_{KOH}=0,2\left(mol\right)\)
\(m_{ddH_2SO_4}=\dfrac{0,2.98}{10\%}=196\left(g\right)\)
b) \(n_{K_2SO_4}=\dfrac{1}{2}n_{KOH}=0,2\left(mol\right)\)
\(m_{ddsaupu}=200+196=396\left(g\right)\)
=> \(C\%_{K2SO4}=\dfrac{0,2.174}{396}.100=8,79\%\)
c) \(3KOH+FeCl_3\rightarrow Fe\left(OH\right)_3+3KCl\)
\(n_{FeCl_3}=n_{Fe\left(OH\right)_3}=\dfrac{1}{3}n_{KOH}=\dfrac{2}{15}\left(mol\right)\)
=>\(V_{FeCl_3}=\dfrac{2}{15}=0,13\left(l\right)\)
\(m_{Fe\left(OH\right)_3}=\dfrac{2}{15}.107=14,27\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
nH2SO4 = 0.2*1=0.2 mol
2NaOH + H2SO4 --> Na2SO4 + H2O
0.4________0.2
mNaOH = 0.4*40=16g
2KOH + H2SO4 --> K2SO4 + H2O
0.4______0.2
mKOH= 0.4*56=22.4g
mddKOH = 22.4*100/5.6=400g
VddKOH = 400/1.045=382.77ml
\(n_{H_2SO_4}=0,2\times1=0,2\left(mol\right)\)
H2SO4 + 2NaOH → Na2SO4 + 2H2O (1)
a) Theo PT1: \(n_{NaOH}=2n_{H_2SO_4}=2\times0,2=0,4\left(mol\right)\)
\(\Rightarrow m_{NaOH}=0,4\times40=16\left(g\right)\)
b) H2SO4 + 2KOH → K2SO4 + 2H2O (2)
Theo PT2: \(n_{KOH}=2n_{H_2SO_4}=2\times0,2=0,4\left(mol\right)\)
\(\Rightarrow m_{KOH}=0,4\times56=22,4\left(g\right)\)
\(\Rightarrow m_{ddKOH}=\frac{22,4}{5,6\%}=400\left(g\right)\)
\(\Rightarrow V_{ddKOH}=\frac{400}{1,045}=382,78\left(ml\right)\)
Đổi 100ml = 0,1 lít
Ta có: \(C_{M_{HCl}}=\dfrac{n_{HCl}}{0,1}=1M\)
=> nHCl = 0,1(mol)
PTHH: KOH + HCl ---> KCl + H2O
Theo PT: \(n_{KOH}=n_{HCl}=0,1\left(mol\right)\)
=> \(m_{KOH}=0,1.56=5,6\left(g\right)\)
Ta có: \(C_{\%_{KOH}}=\dfrac{5,6}{m_{dd_{KOH}}}.100\%=20\%\)
=> \(m_{dd_{KOH}}=28\left(g\right)\)
thanks bro !!