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2K2MnO4-toK2MnO4+MnO2+O2
nKMnO4=15,8/158=0,1 mol
->nK2MnO4=nMnO2=0,05 mol
mcr=0,05.197+0,05.87=14,2g
H,=14,2/14,5=97,7%
\(n_{KMnO_4}=\dfrac{15,8}{158}=0,1mol\)
Gọi \(n_{KMnO_4}=x\)
\(2KMnO_4\rightarrow\left(t^o\right)K_2MnO_4+MnO_2+O_2\)
x 1/2 x 1/2 x ( mol )
Ta có:
\(158\left(0,1-x\right)+\dfrac{1}{2}x\left(197+87\right)=14,52\)
\(\Leftrightarrow x=0,08mol\)
\(H=\dfrac{0,08}{0,1}.100=80\%\)
$n_{Kali} = \dfrac{21,65.36,03\%}{39} = 0,2(mol)$
Gọi $n_{KMnO_4} = a ; n_{KClO_3} = b$
$2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2$
$2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2$
Bảo toàn Kali : $a + b = 0,2$
$n_{O_2} = 0,5a + 1,5b(mol)$
Bảo toàn khối lượng : $158a + 122,5b = 21,65 + (0,5a + 1,5b).32$
Suy ra: a = b = 0,1
$n_{O_2} = 0,5a + 1,5b = 0,2(mol)$
$V_{O_2} = 0,2.22,4 = 4,48(lít)$
Gọi số mol KClO3, KMnO4 trong mỗi phần là a, b (mol)
Phần 1:
\(n_{O_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
mY = 122,5a + 158b - 0,1.32 = 122,5a + 158b - 3,2 (g)
Bảo toàn O: \(n_{O\left(Y\right)}=3a+4b-0,2\left(mol\right)\)
\(\%O=\dfrac{16\left(3a+4b-0,2\right)}{122,5a+158b-3,2}.100\%=34,5\%\)
=> 5,7375a + 9,49b = 2,096 (1)
Phần 2:
PTHH: 2KClO3 --to--> 2KCl + 3O2
a----------->a
2KMnO4 --to--> K2MnO4 + MnO2 + O2
b------------>0,5b------>0,5b
=> 74,5a + 142b = 29,1 (2)
(1)(2) => a = 0,2 (mol); b = 0,1 (mol)
=> \(\left\{{}\begin{matrix}\%m_{KClO_3}=\dfrac{0,2.122,5}{0,2.122,5+0,1.158}.100\%=60,8\%\\\%m_{KMnO_4}=\dfrac{0,1.158}{0,2.122,5+0,1.158}.100\%=39,2\%\end{matrix}\right.\)
2KMnO4-to>K2MnO4+MnO2+O2
0,14-------------0,07------0,07-------0,07 mol
n KMnO4=\(\dfrac{22,12}{158}\)=0,14 mol
=>a=mcr=0,07.197+0,07.87=23,82g
=>VO2=0,07.22,4=1,568l
b)
2Cu+O2-to>2CuO
0,07-----0,14
n Cu=\(\dfrac{10,24}{64}\)=0,16 mol
Cu dư :0,01 mol
m chất rắn =0,01.64+0,14.80=11,84g
\(a)n_{KMnO_4} = a; n_{KClO_3} = b\Rightarrow 158a + 122,5b = 99,95(1)\\ 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ n_{O_2} = 0,5a +1,5b = \dfrac{14,56}{22,4}=0,65(2)\\ (1)(2)\Rightarrow a = 0,4 ; b = 0,3\\ \%m_{KMnO_4} = \dfrac{0,4.158}{99,95}.100\% = 63,23\%\\ \%m_{KClO_3} = 100\%-63,23\% = 36,77\%\)
\(n_{K_2MnO_4} = n_{MnO_2} = 0,5a = 0,2(mol)\\ n_{KClO_3} = b = 0,3(mol)\\ m_{hh\ sau\ pư} = 99,95 - 0,65.32 = 79,15(gam)\\ \%m_{K_2MnO_4} = \dfrac{0,2.197}{79,15}.100\% = 49,78\%\\ \%m_{MnO_2} = \dfrac{0,2.87}{79,15},100\% = 21,98\%\\ \%m_{KCl} = 28,24\%\)
ko khó lém bn ơi có câu nèo easy hơm ko
1) \(n_{O_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
mA = mKMnO4(bđ) - mO2 = 79 - 0,15.32 = 74,2 (g)
PTHH: 2KMnO4 --to--> K2MnO4 + MnO2 + O2
0,3<-----------0,15<----0,15<---0,15
=> \(H=\dfrac{0,3.158}{79}.100\%=60\%\)
2)
\(\left\{{}\begin{matrix}\%m_{K_2MnO_4}=\dfrac{0,15.197}{74,2}.100\%=39,825\%\\\%m_{MnO_2}=\dfrac{0,15.87}{74,2}.100\%=17,588\%\\\%m_{KMnO_4\left(không.pư\right)}=\dfrac{79-0,3.158}{74,2}.100\%=42,587\%\end{matrix}\right.\)
3) \(n_{KMnO_4\left(không.pư\right)}=\dfrac{79}{158}-0,3=0,2\left(mol\right)\)
PTHH: 2KMnO4 + 16HCl --> 2KCl + 2MnCl2 + 5Cl2 + 8H2O
0,2----------------------------------->0,5
K2MnO4 + 8HCl --> 2KCl + MnCl2 + 2Cl2 + 4H2O
0,15-------------------------------->0,3
MnO2 + 4Hcl --> MnCl2 + Cl2 + 2H2O
0,15------------------->0,15
=> \(V_{Cl_2}=22,4\left(0,5+0,3+0,15\right)=21,28\left(l\right)\)
\(n_{KMnO_4}=\dfrac{79}{158}=0,5mol\)
\(n_{O_2}=\dfrac{3,36}{22,4}=0,15mol\)
\(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)
0,5 0,15
a)\(m_{KMnO_4}=0,15\cdot197=29,55g\)
\(m_{MnO_2}=0,15\cdot87=13,05g\)
\(m_{CRắn}=m_{KMnO_4}+m_{MnO_2}=29,55+13,05=42,6g\)
\(n_{KMnO_4pư}=0,15\cdot2=0,3mol\)
\(H=\dfrac{0,3}{0,5}\cdot100\%=60\%\)
b)\(m_{O_2}=0,15\cdot32=4,8g\)
\(\%m_{K_2MnO_4}=\dfrac{29,55}{42,6}\cdot100\%=69,37\%\)
\(\%m_{MnO_2}=100\%-69,37\%=30,63\%\)
1)
Gọi số mol KMnO4, KClO3 là a, b (mol)
=> 158a + 122,5b = 308,2 (1)
PTHH: 2KMnO4 --to--> K2MnO4 + MnO2 + O2
a-------------------------------->0,5a
2KClO3 --to--> 2KCl + 3O2
b------------------>1,5b
=> mO2 = (0,5a + 1,5b).32 = 16a + 48b (g)
mD = 308,2 - 16a - 48b(g)
\(m_{Mn}=\dfrac{\left(308,2-16a-48b\right).10,69}{100}=32,94658-1,7104a-5,1312b\left(g\right)\)
=> \(n_{Mn}=\dfrac{32,94658-1,7104a-5,1312b}{55}=0,6-\dfrac{1069}{34375}a-\dfrac{3207}{34375}\left(mol\right)\)
Mà \(n_{Mn}=n_{KMnO_4}=a\left(mol\right)\)
=> \(\dfrac{35444}{34375}a+\dfrac{3207}{34375}b=0,6\) (2)
(1)(2) => a = 0,4 (mol); b = 2 (mol)
=> \(\left\{{}\begin{matrix}\%m_{KMnO_4}=\dfrac{0,4.158}{308,2}.100\%=20,506\%\\\%m_{KClO_3}=\dfrac{2.122,5}{308,2}.100\%=79,494\%\end{matrix}\right.\)
2)
Giả sử nung 100 (g) đá vôi
=> \(m_{CaCO_3\left(bđ\right)}=\dfrac{80.100}{100}=80\left(g\right)\)
\(m_{rắn.sau.pư}=\dfrac{100.73,6}{100}=73,6\left(g\right)\)
=> mCO2 = 100 - 73,6 = 26,4 (g)
\(n_{CO_2}=\dfrac{26,4}{44}=0,6\left(mol\right)\)
PTHH: CaCO3 --to--> CaO + CO2
0,6<----------------0,6
=> mCaCO3(pư) = 0,6.100 = 60 (g)
\(H\%=\dfrac{60}{80}.100\%=75\%\)
\(a) m_{O_2} = 28,05 - 21,65 = 6,4(gam)\\ n_{O_2} = \dfrac{6,4}{32} = 0,2(mol)\\ V_{O_2} = 0,2.22,4 = 4,48(lít)\\ b) n_{KClO_3} =a ; n_{KMnO_4} = b(mol)\\ \Rightarrow 122,5a + 158b = 28,05(1)\\ 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ n_{O_2} = 1,5a + 0,5b = 0,2(2) (1)(2)\Rightarrow a = b = 0,1\)
\(m_{KClO_3} = 0,1.122,5 = 12,25(gam)\\ m_{KMnO_4} = 0,1.158 = 15,8(gam)\\ n_{K_2MnO_4} = n_{MnO_2} = 0,5b = 0,05(mol)\\ m_{K_2MnO_4} = 0,05.197 = 9,85(gam)\\ m_{MnO_2} = 0,05.87 = 4,35(gam)\\ n_{KCl} = n_{KClO_3} = 0,1(mol)\\ m_{KCl} = 0,1.74,5 = 7,45(gam)\)
PT: \(2KClO_3\xrightarrow[MnO_2]{t^o}2KCl+3O_2\)
\(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)
a, Phần này phải là thể tích O2 chứ nhỉ?
Theo ĐLBT KL, có: mKClO3 + mKMnO4 = m chất rắn + mO2
⇒ mO2 = 28,05 - 21,65 = 6,4 (g)
\(\Rightarrow n_{O_2}=\dfrac{6,4}{32}=0,2\left(mol\right)\Rightarrow V_{O_2}=0,2.22,4=4,48\left(l\right)\)
b, Giả sử: \(\left\{{}\begin{matrix}n_{KClO_3}=x\left(mol\right)\\n_{KMnO_4}=y\left(mol\right)\end{matrix}\right.\)
⇒ 122,5x + 158y = 28,05 (1)
Theo PT: \(n_{O_2}=\dfrac{3}{2}x+\dfrac{1}{2}y\left(mol\right)\)
\(\Rightarrow\dfrac{3}{2}x+\dfrac{1}{2}y=0,2\left(2\right)\)
Từ (1) và (2) ⇒ x = y = 0,1 (mol)
⇒ mKClO3 = 122,5.0,1 = 12,25 (g)
mKMnO4 = 0,1.158 = 15,8 (g)
Theo PT: \(\left\{{}\begin{matrix}n_{KCl}=n_{KClO_3}=0,1\left(mol\right)\\n_{K_2MnO_4}=n_{MnO_2}=\dfrac{1}{2}n_{KMnO_4}=0,05\left(mol\right)\end{matrix}\right.\)
⇒ mKCl = 0,1.74,5 = 7,45 (g)
mK2MnO4 = 0,05.197 = 9,85 (g)
mMnO2 = 0,05.87 = 4,35 (g)
Bạn tham khảo nhé!
c2
a/ 2KMnO4(x)to→K2MnO4(0,5x)+MnO2(0,5x)+O2(0,5x)
Gọi số mol của KMnO4 tham gia phản ứng là x.
⇒mKMnO4=158x(g)
⇒mK2MnO4=0,5x.197=98,5x(g)
⇒mMnO2=0,5x.87=43,5x(g)
⇒22,12−158x+98,5x+43,5x=21,26
⇔x=0,05375(mol)
⇒VO2=0,05375.0,5.22,4=0,602(l)
b/ mKMnO4(pứ)=0,05375.158=8,4925(g)
⇒%KMnO4=8,4925\22,12.100%=38,39%