Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(n_{NaOH}=0,25.V\left(mol\right)\)
\(n_{Ca\left(OH\right)_2}=0,5.V\left(mol\right)\)
=> \(n_{OH^-}=0,25.V+2.0,5.V=1,25V\left(mol\right)\)
\(n_{HCl}=0,55.2=1,1\left(mol\right)=>n_{H^+}=1,1\left(mol\right)\)
H+ + OH- --> H2O
1,1->1,1
=> 1,25.V = 1,1
=> V = 0,88(l)
a)PTHH:
HCl + NaOH → NaCl + H2O
nHCl = 0,04 (mol) = nNaOH = nNaCl
=>VddNaOH = 0,04/0,1 = 0,4 (l) = 400 (ml)
Vdd = VddNaOH + VddHCl = 0,6 (l)
=>C(M) ≈ 0,067 (M)
b) 2HCl + Ca(OH)2 → CaCl2 + 2H2O
nCa(OH)2 = nCaCl2 = (1/2)nHCl = 0,02 (mol)
(Nồng độ phần trăm = 25% ????)
mCa(OH)2 = 1,48 (g)
=>mdd(Ca(OH)2) = 5,92 (g)
mddHCl = 220 (g)
=>mdd = 225,92 (g)
mCaCl2 = 2,22 (g)
=>%mCaCl2 ≈ 0,98%
Theo đề bài ta có : nHCl = 0,2.0,2=0,04(mol)
a) Ta có PTHH :
\(HCl+NaOH\rightarrow NaCl+H2O\)
0,04mol.....0,04mol....0,04mol
Ta có :
\(V_{\text{dd}HCl\left(c\text{ần}-d\text{ùng}\right)}=\dfrac{0,04}{0,1}=0,4\left(lit\right)=400\left(ml\right)\)
CMNaCl = \(\dfrac{0,04}{0,2}=0,2\left(M\right)\)
b) Theo đề bài ta có : mddHCl=\(200.1=200\left(g\right)\)
Ta có PTHH :
\(Ca\left(OH\right)2+2HCl\rightarrow CaCl2+2H2O\)
0,02mol...........0,04mol....0,02mol
Ta có :
\(m\text{dd}Ca\left(OH\right)2\left(c\text{ần}-d\text{ùng}\right)=\dfrac{0,02.74}{5}.100=29,6\left(g\right)\)
C%CaCl2 = \(\dfrac{0,02.111}{0,02.74+200}.100\%\approx1,102\%\)
Vậy..............
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: \(n_{KOH}=2n_{H_2SO_4}=2\times0,2=0,4\left(mol\right)\)
\(\Rightarrow m_{KOH}=0,4\times56=22,4\left(g\right)\)
\(\Rightarrow m_{ddKOH}=\frac{22,4}{5,6\%}=400\left(g\right)\)
\(\Rightarrow V_{ddKOH}=\frac{400}{1,045}=382,78\left(ml\right)\)
nH2SO4=0,02.1=0,02(mol)nH2SO4=0,02.1=0,02(mol)
PTHH: H2SO4+2NaOH→Na2SO4+2H2OH2SO4+2NaOH→Na2SO4+2H2O
pư..............0,02..........0,04..............0,02...........0,04 (mol)
⇒mNaOH=0,04.40=1,6(g)⇒mNaOH=0,04.40=1,6(g)
⇒mddNaOH(20%)=1,620%=8(g)⇒mddNaOH(20%)=1,620%=8(g)
PTHH: H2SO4+2KOH→K2SO4+2H2OH2SO4+2KOH→K2SO4+2H2O
pư............0,02............0,04............0,02..........0,04 (mol)
⇒mKOH=0,04.56=2,24(g)⇒mKOH=0,04.56=2,24(g)
⇒mddKOH(5,6%)=2,245,6%=40(g)⇒mddKOH(5,6%)=2,245,6%=40(g)
⇒VKOH=401,045≈38,28(ml)
a, nH2SO4=0.02*1=0.02(mol)
H2SO4 + NaOH ➞ Na2SO4 +H2O
0.02.........0.02........0.02.........0.02.......(mol)
m dung dịch NaOH=(0.02*40)*100/20=4(g)
b) H2SO4 + KOH ➞ K2SO4 +H2O
....0.02.......0.02..........0.02......0.02...(mol)
mdung dịch KOH=(0.02*56)*100/5.6=20(g)
Vdung dịch=20/1.045=19.139(ml)
nHCl=CM.V=1.0,6=0,6(mol)
Pt: HCl+ NaOH-> NaCl + H2O
cứ:1.............1.............1 (mol)
vậy:0,6----->0,6------>0,6(mol)
=> mNaOH=0,6.40=24(g)
\(\Rightarrow m_{ddNaOH}=\dfrac{m_{NaOH}.100\%}{C\%}=\dfrac{24.100}{30}=80\left(g\right)\)
b) Nếu thay NaOH bằng Ca(OH)2 thì ta có PT:
PT: 2HCl + Ca(OH)2 -> CaCl2 +2H2O
Cứ:2................1.................1 (mol)
Vậy: 0,6------->0,3----------->0,3(mol)
=> mCa(OH)2=n.M=0,3.74=22,2(g)
\(\Rightarrow m_{ddCa\left(OH\right)_2}=\dfrac{m_{Ca\left(OH\right)_2}.100\%}{C\%}=\dfrac{22,2.100}{7,351}\approx302\left(g\right)\)
\(\Rightarrow V_{ddCa\left(OH\right)_2}=\dfrac{m_{ddCa\left(OH\right)_2}}{D}=\dfrac{302}{1,045}\approx289\left(ml\right)=0,289\left(lít\right)\)