Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Bài 1: nH2SO4=0.06 mol; nHNO3=0.2 mol
nCa(OH)2=3a.0,4=1.2a(mol)
nNaOH=0,4.2a= 0.8a (mol)
Quy đổi hỗn hợp về HNO3 => nHNO3=0.2+0.06.2=0.32mol
PTHH: 2HNO3 + Ca(OH)2 ----> Ca(NO3)2 + 2H2O
Mol 2,4a 1,2a
HNO3+ NaOH -----> NaNO3 + H2O
0,8a 0,8a
=> 2,4a + 0,8a=0.32 => a = 0.1 (mol)
1.NaOH+HCl--->NaCl+H2O
nNaOH=(200.10%)/40=0,5
=>nHCl=nNaOH=0,5
=>mddHCl=(0,5.36,5)/3,65%=500 g
2:a,2NaOH+H2SO4−−>Na2SO4+H2O2
Theo pthh, ta có: nNaOH=2.nH2SO4=0,4mol
-->mNaOH=16g
-->md/dNaOH=80g
b, Ta có: nKOH=0,4mol
-->md/dKOH=400g
-->V=383ml
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..............
a) NaOH+HCl---->NaCl+H2O
n HCl=0,2.2=0,4(mol)
Theo pthh
n NaOH =n HCl =0,4(mol)
V NaOH= 0,4/0,1=4(l)=400ml
b) Ca(OH)2+2HCl---->CaCl2+2H2O
Theo pthhj
n Ca(OH)2=1/2 n HCl =0,2(mol)
m Ca(OH)2=\(\frac{0,2.74.100}{5}=296\left(g\right)\)
Bài 2
Ca(OH)2+2HCl---->CaCl2+2H2O
n HCl=0,2.2=0,4(mol)
Theo pthh
n Ca(OH)2=1/2 n HCl =0,2(mol)
m Ca(OH)2=\(\frac{0,2.74.200}{10}=148\left(g\right)\)
Bài 3
H2SO4+2NaOH--->Na2SO4+H2O
n H2SO4=0,2.1=0,2(mol)
Theo pthh
n NaOH =2n H2SO4=0,4(mol)
m NaOH=\(\frac{0,4.40.100}{20}=80\left(g\right)\)
Bài 4
HCl+NaOH---->NaCl+H2O
n HCl=0,2.1=0,2(mol)
Theo pthh
n NaCl =n HCl =0,2(mol)
m NaCl=0,2.58,5=11,7(g)
n NaOH =n HCl=0,2(mol)
m NaOH=\(\frac{0,2.40.100}{20}=40\left(g\right)\)
Câu 1:
\(\text{n hcl = 0,2.0,2 = 0,04 mol}\)
\(\text{a, naoh + hcl ---> nacl + h2o}\)
n naoh = n hcl = 0,04 mol
\(\Rightarrow\text{V naoh = 0,04 ÷ 0,1 = 0,4 lít --> V = 400ml}\)
b, \(\text{ca(oh)2 + 2hcl ---> cacl2 +2 h2o}\)
n ca(oh)2 =1/2. n hcl = 0 ,02 mol
\(\Rightarrow\text{--> m dd ca(oh)2 = 0,02. 74÷ 5 .100 = 29,6g}\)
Câu 2 :
\(\text{ n hcl = 0,2.2 = 0,4 mol}\)
\(\text{ca(oh)2 + 2hcl ---> cacl2 +2 h2o}\)
n ca(oh)2 =1/2. n hcl = 0 ,2 mol
\(\Rightarrow\text{m dd Ca(OH)2 = 0,2.74÷10.100 = 148g}\)
Câu 3:
\(\text{2NaOH + H2SO4 -> Na2SO4 + H2O}\)
Ta có : nH2SO4=0,2.1=0,2 mol
Theo ptpu: nNaOH=2nH2SO4=0,2.2=0,4 mol
\(\text{-> mNaOH=0,4.40=16 gam }\)
m dung dịch NaOH=16/20%=80 gam
Câu 4
\(\text{NaOH + HCl -> NaCl + H2O}\)
Ta có: nHCl=0,2.1=0,2 mol
Theo ptpu: nNaOH=nNaCl=nHCl=0,2 mol
\(\Rightarrow\text{mNaOH=0,2.40=8 gam}\)
\(\Rightarrow\text{m dung dịch NaOH=8/20%=40 gam}\)
muối là NaCl 0,2 mol -> mNaCl=0,2.58,5=11,7 gam
a) H3PO4+3KOH----> K3PO4+3H2O
b) n\(_{H3PO4}=0,1.2=0,2\left(mol\right)\)
Theo pthh
n\(_{KOH}=3n_{H3PO4}=0,6\left(mol\right)\)
m\(_{ddKOH}=\frac{0,6.56.100}{20}=168\left(g\right)\)
c) 2H3PO4+3Ca(OH)2---> Ca3(PO4)2+6H2O
Theo pthh
n\(_{Ca\left(OH\right)2}=\frac{3}{2}n_{H3PO4}=0,3\left(mol\right)\)
m\(_{ddCa\left(OH\right)2}=\frac{0,3.74.100}{7,4}=300\left(g\right)\)
V\(_{C_{ }a\left(OH\right)2}=300.1,05=315ml\)
nH3PO4 = 0,2 (mol)
PTHH: H3PO4 +3KOH--->K3PO4+3H2O(1)
2H3PO4+3Ca(OH)2--->Ca3(PO4)2+6H2O(2)
Theo PT(1)
=>nKOH = 3nH3PO4 = 0,6 (mol)
=> mdd KOH = 168g
Theo PT(2)
=> nCa(OH)2 = 0,3 (mol)
=> mddCa(OH)2 = 300(g)
=> VCa(OH)2 = 300. 1,05 = 315ml
3KOH + H3PO4---->K3PO4 +3H2O
a) Ta có
n\(_{H3PO4}=0,2.2=0,4\left(mol\right)\)
Theo pthh
n\(_{KOH}=3n_{H3PO4}=1,2\left(mol\right)\)
m\(_{ddKOH}=\frac{1,2.55.100}{20}=330\left(g\right)\)
b) m\(_{H3PO4}=200.1,2=240\left(g\right)\)
Theo pthh
n\(_{K3PO4}=n_{H3PO4}=0,4\left(mol\right)\)
C%=\(\frac{0,4.173}{240+330}.100\%=12,14\%\)
Ta có : nH3PO4 = 2.0,2 = 0,4 (mol)
PTHH : H3PO4+ 3KOH--->K3PO4+3H2O
=>nKOH = 1,2 (mol)
=>mKOH = 330(g)
mH3PO4 = 240(g)
=>nK3PO4 = nH3PO4 = 0,4 (mol)
=>C% = 12,14%