Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(n_{Al}=\dfrac{1,728}{27}=0,064\left(mol\right)\)
PTHH: 4Al + 3O2 --to--> 2Al2O3
____0,064->0,048
=> mO2 = 0,048.32 = 1,536 (g)
\(m_B=\dfrac{0,894.100}{8,127}=11\left(g\right)\)
Theo ĐLBTKL: mA = mB + mO2
=> mA = 11 + 1,536 = 12,536 (g)
Gọi x, y lần lượt là số mol của KMnO4 và KClO3.
Theo đề, ta có: 158x + 122,5y = 56,1 (*)
Ta có: \(n_{O_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\)
PTHH:
\(2KMnO_4\overset{t^o}{--->}K_2MnO_4+MnO_2+O_2\left(1\right)\)
\(2KClO_3\xrightarrow[MnO_2]{t^o}3KCl+3O_2\left(2\right)\)
Theo PT(1): \(n_{O_2}=\dfrac{1}{2}.n_{KMnO_4}=\dfrac{1}{2}x\left(mol\right)\)
Theo PT(2): \(n_{O_2}=\dfrac{3}{2}.n_{KClO_3}=\dfrac{3}{2}y\left(mol\right)\)
\(\Rightarrow\dfrac{1}{2}x+\dfrac{3}{2}y=0,4\) (**)
Từ (*) và (**), ta có HPT:
\(\left\{{}\begin{matrix}158x+122,5y=56,1\\\dfrac{1}{2}x+\dfrac{3}{2}y=0,4\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0,2\\y=0,2\end{matrix}\right.\)
\(\Rightarrow m_{KMnO_4}=158.0,2=31,6\left(g\right)\)
\(m_{KClO_3}=0,2.122,5=24,5\left(g\right)\)
a) Gọi số mol KMnO4, KClO3 là a, b (mol)
=> \(\left\{{}\begin{matrix}n_K=a+b\left(mol\right)\\n_{Mn}=a\left(mol\right)\\n_{Cl}=b\left(mol\right)\\n_O=4a+3b\left(mol\right)\end{matrix}\right.\)
Có \(n_O=\dfrac{9}{14}\Sigma_n\)
=> \(4a+3b=\dfrac{9}{14}\left(a+b+a+b+4a+3b\right)\)
=> \(\dfrac{1}{7}a-\dfrac{3}{14}b=0\) (1)
PTHH: 2KMnO4 --to--> K2MnO4 + MnO2 + O2
a------------------------------->0,5a
2KClO3 --to--> 2KCl + 3O2
b------------------>1,5b
=> \(0,5a+1,5b=\dfrac{10,08}{22,4}=0,45\) (2)
(1)(2) => a = 0,3 (mol); b = 0,2 (mol)
=> m = 0,3.158 + 0,2.122,5 = 71,9 (g)
b) \(\left\{{}\begin{matrix}\%m_{KMnO_4}=\dfrac{0,3.158}{71,9}.100\%=65,925\%\\\%m_{KClO_3}=\dfrac{0,2.122,5}{71,9}.100\%=34,075\%\end{matrix}\right.\)
\(a)n_{KMnO_4} = a; n_{KClO_3} = b\Rightarrow 158a + 122,5b = 99,95(1)\\ 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ n_{O_2} = 0,5a +1,5b = \dfrac{14,56}{22,4}=0,65(2)\\ (1)(2)\Rightarrow a = 0,4 ; b = 0,3\\ \%m_{KMnO_4} = \dfrac{0,4.158}{99,95}.100\% = 63,23\%\\ \%m_{KClO_3} = 100\%-63,23\% = 36,77\%\)
\(n_{K_2MnO_4} = n_{MnO_2} = 0,5a = 0,2(mol)\\ n_{KClO_3} = b = 0,3(mol)\\ m_{hh\ sau\ pư} = 99,95 - 0,65.32 = 79,15(gam)\\ \%m_{K_2MnO_4} = \dfrac{0,2.197}{79,15}.100\% = 49,78\%\\ \%m_{MnO_2} = \dfrac{0,2.87}{79,15},100\% = 21,98\%\\ \%m_{KCl} = 28,24\%\)
ko khó lém bn ơi có câu nèo easy hơm ko
2.
a) 2Na + O2 -> 2NaO
b) P2O5 + 3H2O -> 2H3PO4
c) HgO -> Hg + 1/2O2
d) 2Fe(OH)3 -> Fe2O3 + 3H2O
e) Na2CO3 + CaCl2 -> CaCO3 + 2NaCl
CHÚC BẠN HỌC TỐT!!
Câu 1: Gọi x,y lần lượt là sô mol của \(KMnO_4\) và \(KClO_3\)
PTHH: \(2KMnO_4\underrightarrow{o}K_2MnO_4+MnO_2+O_2\uparrow\)
pư...............x..................\(\dfrac{x}{2}\)...................\(\dfrac{x}{2}\)..........\(\dfrac{x}{2}\) (mol)
PTHH: \(2KClO_3\underrightarrow{o}2KCl+3O_2\uparrow\)
pư................y...............y............1,5y (mol)
Theo đề bài, ta có:\(\left\{{}\begin{matrix}n_{O2}=\dfrac{10,08}{22,4}=0,45\left(mol\right)\\\dfrac{SPT_{KMnO4}}{SPT_{KClO3}}=2\Rightarrow n_{KMnO4}=2n_{KClO3}\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\dfrac{x}{2}+1,5y=0,45\\x=2y\Rightarrow x-2y=0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=0,36\\y=0,18\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{K2MnO4}=\dfrac{0,36}{2}.\left(2.39+55+4.16\right)=35,46\left(g\right)\\m_{MnO2}=\dfrac{0,36}{2}.\left(55+2.16\right)=15,66\left(g\right)\\m_{KCl}=0,18.\left(39+35,5\right)=13,41\left(g\right)\end{matrix}\right.\)
CHÚC BẠN HỌC TỐT!!
Câu 2: Gọi x, y lầm lượt là số mol của S và C.
PTHH: \(S+O_2\underrightarrow{o}SO_2\)
pư.........x........x........x (mol)
PTHH: \(C+O_2\underrightarrow{o}CO_2\)
pư..........y.......y..........y (mol)
Theo đề bài, ta có: \(\left\{{}\begin{matrix}m_{hhA}=13,5\left(g\right)\\M_{hhB}=32.1,84375=59\left(\dfrac{g}{mol}\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_S+m_C=13,5\\\dfrac{m_{SO2}+m_{CO2}}{M_{hhB}}=x+y\Rightarrow\dfrac{64x+44y}{59}=x+y\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}32x+12y=13,5\\5x-15y=0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=0,375\\y=0,125\end{matrix}\right.\)
a) \(\left\{{}\begin{matrix}m_S=32.0,375=12\left(g\right)\\m_C=12.0,125=1,5\left(g\right)\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}\%S=\dfrac{12}{13,5}.100\%\approx88,89\%\\\%C=\dfrac{1,5}{13,5}.100\%\approx11,11\%\end{matrix}\right.\)
b) \(V_{O2}=22,4.\left(0,375+0,125\right)=11,2\left(l\right)\left(đktc\right)\)
Vậy..........