Nhiệt phân hoàn toàn 24,5g potassium chlorate
a Viết PTHH và tính thể tích khí oxygen thu được ở đktc
b Đốt cháy 11,2g sắt bằng lượng khí oxygen thu được ở trên.Tính khối lượng sản phẩm
Giúp mik vs
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`2KClO_3->2KCl+3O_2`(to)
0,04-----------0,02-----0,06
`n_(KClO_3)=(4,9)/(122,5)=0,04mol`
=>`V_(O_2)=0,06.24,79=1,4847l`
c)
`4P+5O_2->2P_2O_5`(to)
0,048----0,06 mol
`=>m_P=0,048.31=1,488g`
\(n_{KClO_3}=\dfrac{24,5}{122,5}=0,2mol\)
a)\(2KClO_3\underrightarrow{t^o}2KCl+3O_2\)
0,2 0,3
b)\(V_{O_2}=0,3\cdot22,4=6,72l\)
c)Bảo toàn khối lượng:
\(m_{Fe}+m_{O_2}=m_{sp}\)
\(\Rightarrow m_{sp}=11,2+0,3\cdot32=20,8g\)
Bài 2:
a) 2Mg + O2 --to--> 2MgO
b) \(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)
PTHH: 2Mg + O2 --to--> 2MgO
_______0,2->0,1------>0,2
=> VO2 = \(\dfrac{0,1.0,082.\left(273+25\right)}{0,99}=2,468\left(l\right)\)
c) mMgO = 0,2.40 = 8(g)
Bài 3
a) Theo ĐLBTKL: mMg + mO2 = mMgO (1)
b) (1) => mMgO = 2,4 + 1,6 = 4(g)
c) \(nO_2=\dfrac{1,6}{32}=0,05\left(mol\right)\)
=> Số phân tử O2 = 0,05.6.1023 = 0,3.1023
`#3107.101107`
1.
a.
Ta có:
\(\text{n}_{\text{KClO}_3}=\dfrac{\text{m}_{\text{KClO}_3}}{\text{M}_{\text{KClO}_3}}=\dfrac{122,5}{122,5}=1\text{ (mol)}\)
PTPỨ: \(\text{2KClO}_3\text{ }\)\(\underrightarrow{\text{ }t^0}\) \(\text{2KCl}+3\text{O}_2\)
Ta có: `2` mol \(\text{KClO}_3\) thu được `3` mol \(\text{O}_2\)
`=>` `1` mol \(\text{KClO}_3\) thu được `1,5` mol \(\text{O}_2\)
b.
\(\text{V}_{\text{O}_2}=\text{n}_{\text{O}_2}\cdot24,79=1,5\cdot24,79=37,185\left(l\right)\)
TTĐ:
\(m_{KClO_3}=122,5\left(g\right)\)
______________
a) PTHH?
b) \(V_{O_2}=?\left(l\right)\)
Giải
\(n_{KClO_3}=\dfrac{m}{M}=\dfrac{122,5}{122,5}=1\left(mol\right)\)
\(2KClO_3\underrightarrow{t^o}2KCl+3O_2\uparrow\)
1-> 1 : 1,5(mol)
\(V_{O_2}=n.22,4=1,5.22,4=33,6\left(l\right)\)
a. \(n_{KMnO_4}=\dfrac{47.4}{158}=0,3\left(mol\right)\)
PTHH : 2KMnO4 ---to----> K2MnO4 + MnO2 + O2
0,3 0,15
\(V_{O_2}=0,15.22,4=3,36\left(l\right)\)
b. PTHH : 4Al + 3O2 -> 2Al2O3
0,2 0,15
\(m_{Al}=0,2.27=5,4\left(g\right)\)
a, PT: \(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)
Ta có: \(n_{KMnO_4}=\dfrac{31,6}{158}=0,2\left(mol\right)\)
Theo PT: \(n_{K_2MnO_4}=\dfrac{1}{2}n_{KMnO_4}=0,1\left(mol\right)\)
\(\Rightarrow m_{K_2MnO_4}=0,1.197=19,7\left(g\right)\)
b, Theo PT: \(n_{O_2}=\dfrac{1}{2}n_{KMnO_4}=0,1\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,1.24,79=2,479\left(l\right)\)
c, PT: \(CH_4+2O_2\underrightarrow{t^o}CO_2+2H_2O\)
Theo PT: \(\left\{{}\begin{matrix}n_{CO_2}=\dfrac{1}{2}n_{O_2}=0,05\left(mol\right)\\n_{H_2O}=n_{O_2}=0,1\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow V_{CO_2}=0,05.24,79=1,2395\left(l\right)\)
\(m_{H_2O}=0,1.18=1,8\left(g\right)\)
\(n_P=\dfrac{0,62}{31}=0,02\left(mol\right)\\ 4P+5O_2\rightarrow\left(t^o\right)2P_2O_5\\ n_{P_2O_5}=\dfrac{2}{4}.0,02=0,01\left(mol\right);n_{O_2}=\dfrac{5}{4}.0,02=0,025\left(mol\right)\\ V_{O_2\left(đkc\right)}=0,025.24,79=0,61975\left(l\right)\\ m_{P_2O_5}=142.0,01=1,42\left(g\right)\)
\(n_P=\dfrac{m}{M}=\dfrac{0,62}{31}=0,02mol\)
PTHH: \(4P+5O_2\underrightarrow{t^o}2P_2O_5\)
4 5 2 ( mol )
0,02 0,025 0,01 ( mol )
\(V_{O_2}=n_{O_2}.22,4=0,025.22,4=0,56l\)
\(m_{P_2O_5}=n_{P_2O_5}.M_{P_2O_5}=0,01.142=1,42g\)
a. \(n_{KClO_3}=\dfrac{24,5}{122,5}=0,2\left(mol\right)\)
PTHH : 2KClO3 -to> 2KCl + 3O2
0,2 0,3
\(V_{O_2}=0,3.22,4=6,72\left(l\right)\)
b.\(n_{O_2}=0,3\left(mol\right)\left[cmt\right]\)
\(m_{O_2}=0,3.32=9,6\left(g\right)\)
PTHH : 3Fe + 2O2 -to> Fe3O4
Theo ĐLBTKL
\(m_{Fe}+m_{O_2}=m_{Fe_3O_4}\\ \Rightarrow11,2+9,6=20,8\left(g\right)\)
a: \(2KClO_3\rightarrow2KCl+3O_2\)
\(n_{KClO_3}=\dfrac{24.5}{122.5}=0.2\left(mol\right)\)
\(\Leftrightarrow n_{O_2}=\dfrac{3}{2}\cdot0.2=0.3\left(mol\right)\)
\(V_{O_2}=0.3\cdot22.4=6.72\left(lít\right)\)
b: \(4Fe+3O_2\rightarrow2Fe_2O_3\)
\(n_{Fe}=\dfrac{11.2}{56}=0.2\left(mol\right)\)
\(\dfrac{n_{Fe}}{4}=\dfrac{0.2}{4}=0.05< \dfrac{n_{O_2}}{3}\) nên O2 dư
=>Tính theo Fe
\(n_{Fe_2O_3}=0.1\left(mol\right)\)
\(m_{Fe_2O_3}=0.1\cdot160=16\left(g\right)\)