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Câu 16:
PTHH: \(KOH+HCl\rightarrow KCl+H_2O\)
Ta có: \(n_{HCl}=0,25\cdot1,5=0,375\left(mol\right)=n_{KOH}=n_{KCl}\)
\(\Rightarrow\left\{{}\begin{matrix}V_{KOH}=\dfrac{0,375}{2}=0,1875\left(l\right)\\C_{M_{KCl}}=\dfrac{0,375}{0,1875+0,25}\approx0,86\left(M\right)\end{matrix}\right.\)
Câu 18:
PTHH: \(2KOH+H_2SO_4\rightarrow K_2SO_4+2H_2O\)
a) Ta có: \(n_{H_2SO_4}=\dfrac{200\cdot14,7\%}{98}=0,3\left(mol\right)\)
\(\Rightarrow n_{KOH}=0,6\left(mol\right)\) \(\Rightarrow m_{ddKOH}=\dfrac{0,6\cdot56}{5,6\%}=600\left(g\right)\) \(\Rightarrow V_{ddKOH}=\dfrac{600}{10,45}\approx57,42\left(ml\right)\)
b) Theo PTHH: \(n_{K_2SO_4}=0,3\left(mol\right)\) \(\Rightarrow C\%_{K_2SO_4}=\dfrac{0,3\cdot174}{600+200}\cdot100\%=6,525\%\)
Ta có: \(C_{\%_{H_2SO_4}}=\dfrac{m_{H_2SO_4}}{200}.100\%=14,7\%\)
=> \(m_{H_2SO_4}=29,4\left(g\right)\)
=> \(n_{H_2SO_4}=\dfrac{29,4}{98}=0,3\left(mol\right)\)
a. PTHH: 2KOH + H2SO4 ---> K2SO4 + 2H2O
Theo PT: \(n_{KOH}=2.n_{H_2SO_4}=2.0,3=0,6\left(mol\right)\)
=> \(m_{KOH}=0,6.56=33,6\left(g\right)\)
Ta có: \(C_{\%_{KOH}}=\dfrac{33,6}{m_{dd_{KOH}}}.100\%=5,6\%\)
=> \(m_{dd_{KOH}}=600\left(g\right)\)
Theo đề, ta có:
\(D=\dfrac{600}{V_{dd_{KOH}}}=10,45\)(g/ml)
=> \(V_{dd_{KOH}}=57,42\left(ml\right)\)
b. Ta có: \(m_{dd_{K_2SO_4}}=200+33,6=233,6\left(g\right)\)
Theo PT: \(n_{K_2SO_4}=n_{H_2SO_4}=0,3\left(mol\right)\)
=> \(m_{K_2SO_4}=0,3.174=52,2\left(g\right)\)
=> \(C_{\%_{K_2SO_4}}=\dfrac{52,2}{233,6}.100\%=22,35\%\)
PTHH: \(H_2SO_4+2KOH\rightarrow K_2SO+2H_2O\)
Ta có: \(n_{H_2SO_4}=0,2\cdot1=0,2\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}n_{KOH}=0,4\left(mol\right)\\n_{K_2SO_4}=0,2\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{ddKOH}=\dfrac{\dfrac{0,4\cdot56}{6\%}}{1,048}\approx356,2\left(ml\right)\\C_{M_{K_2SO_4}}=\dfrac{0,2}{0,2+0,3562}\approx0,36\left(M\right)\end{matrix}\right.\)
\(n_{H_2SO_4}=1.0,2=0,2\left(mol\right)\\ H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O\\ 0,2.........0,4........0,2.......0,2\left(mol\right)\\ a.m_{ddKOH}=\dfrac{0,4.56.100}{6}=\dfrac{1120}{3}\left(g\right)\\ V_{ddKOH}=\dfrac{\dfrac{1120}{3}}{1,048}=\dfrac{140000}{393}\left(ml\right)\approx0,356\left(l\right)\)
\(b.C_{MddK_2SO_4}=\dfrac{0,2}{\dfrac{140000}{393}+0,2}\approx0,00056\left(M\right)\)
mH2SO4 = 200 . 14,7 % = 29,4 g
=> nH2SO4 = 29,4 : 98 = 0,3 mol
PT : 2KOH + H2SO4 -> K2SO4 + 2H2O
0,6 0,3 0,3
mKOH = 0,3 . 56 = 16,8 g
=> mddKOH = 16,8 .100 : 5,6 = 300 g
=> VddKOH = 300 : 10,45 = 28,71 ml
Kl dd sau phản ứng là
300 + 200 = 500 g
mK2SO4 = 0,3 . 174 = 52,2 g
Nồng độ % K2SO4 là
C% = 52,2 / 500 . 100 =10,5 %
m H2SO4=(200*14,7%)/100%=29,4 g => nH2SO4= 0,3 mol
PT 2KOH+ H2SO4=> K2SO4+ 2H2O
mol 0,6 0,3 0,3
mKOH= 0,6*56=33,6 g=> mdd KOH= (33,6*100)/5,6=600g
V KOH= 600*10,45=6270 ml=6,27 l
mdd spu= 600+200=800 g , mK2SO4= 0,3*174=52,2 g
C%K2SO4=(52,2*100%)/800= 6,525%
2KOH + H2SO4 → K2SO4 + 2H2O
\(m_{H_2SO_4}=200\times14,7\%=29,4\left(g\right)\)
\(\Rightarrow n_{H_2SO_4}=\dfrac{29,4}{98}=0,3\left(mol\right)\)
Theo PT: \(n_{KOH}=2n_{H_2SO_4}=2\times0,3=0,6\left(mol\right)\)
\(\Rightarrow m_{KOH}=0,6\times56=33,6\left(g\right)\)
\(\Rightarrow m_{ddKOH}=\dfrac{33,6}{5,6\%}=600\left(g\right)\)
\(\Rightarrow V_{ddKOH}=\dfrac{600}{10,45}=57,42\left(ml\right)\)
Theo PT: \(n_{K_2SO_4}=n_{H_2SO_4}=0,3\left(mol\right)\)
\(\Rightarrow m_{K_2SO_4}=0,3\times174=52,2\left(g\right)\)
\(m_{ddK_2SO_4}=m_{ddKOH}+m_{ddH_2SO_4}=600+200=800\left(g\right)\)
\(\Rightarrow C\%_{K_2SO_4}=\dfrac{52,2}{800}\times100\%=6,525\%\)
a) 2KOH+H2SO4--->K2SO4+2H2O
m H2SO4=200.14,7/100=29,4(g)
n H2SO4=29,4/98=0,3(mol)
n KOH=2n H2SO4=0,6(mol)
m KOH=0,6.56=33,6(g)
m dd KOH=33,6.100/5,6=600(g)
V KOH=600/10,45=57,42(ml)
b) m dd sau pư=600+200=800(g)
n K2SO4=n H2SO4=0,3(mol)
m K2SO4=174.0,3=52,2(g)
C% K2SO4=52,2/800.100%=6,525%
\(n_{H_2SO_4}=0,15.1=0,15\left(mol\right)\)
PT: \(2KOH+H_2SO_4\rightarrow K_2SO_4+2H_2O\)
Theo PT: \(n_{KOH}=2n_{H_2SO_4}=0,3\left(mol\right)\)
\(\Rightarrow m_{KOH}=0,3.56=16,8\left(g\right)\)
\(\Rightarrow m_{ddKOH}=\dfrac{16,8}{5,6\%}=300\left(g\right)\)
\(\Rightarrow V_{ddKOH}=\dfrac{300}{10,45}\approx28,71\left(ml\right)\)
mH2SO4 = \(\dfrac{200.14,7\%}{100\%}\)= 29,4 (g)
nH2SO4 = \(\dfrac{29,4}{98}\)= 0,3 (mol)
2KOH + H2SO4 ----> K2SO4 + 2H2O
0,6 0,3 0,3 0,6 (mol)
=> mKOH = 0,6.56 = 33,6 (g)
=> mdd KOH = \(\dfrac{33,6.100\%}{5,6\%}\) = 600 (g)
=> VKOH = \(\dfrac{600}{110,45}\)= 5,4 (l)