Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a, PT: \(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)
b, Ta có: \(n_{KMnO_4}=\dfrac{3,16}{158}=0,02\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{1}{2}n_{KMnO_4}=0,01\left(mol\right)\)
\(\Rightarrow m_{O_2}=0,01.32=0,32\left(g\right)\)
c, \(V_{O_2}=0,01.24,79=0,2479\left(l\right)\)
a, PT: \(2KClO_3\underrightarrow{t^o}2KCl+3O_2\)
Ta có: \(n_{KClO_3}=\dfrac{24,5}{122,5}=0,2\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{3}{2}n_{KClO_3}=0,3\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,3.24,79=7,437\left(g\right)\)
b, PT: \(2Cu+O_2\underrightarrow{t^o}2CuO\)
Ta có: \(n_{Cu}=\dfrac{32}{64}=0,5\left(mol\right)\)
Xét tỉ lệ: \(\dfrac{0,5}{2}< \dfrac{0,3}{1}\), ta được O2 dư.
Theo PT: \(\left\{{}\begin{matrix}n_{O_2\left(pư\right)}=\dfrac{1}{2}n_{Cu}=0,25\left(mol\right)\\n_{CuO}=n_{Cu}=0,5\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow n_{O_2\left(dư\right)}=0,3-0,25=0,05\left(mol\right)\)
\(\Rightarrow m_{O_2\left(dư\right)}=0,05.32=1,6\left(g\right)\)
\(m_{CuO}=0,5.80=40\left(g\right)\)
\(n_{KClO_3}=\dfrac{7}{122,5}=\dfrac{2}{35}\left(mol\right)\)
PTHH :
\(2KClO_3\underrightarrow{t^o}2KCl+3O_2\)
2/35 2/35 3/35
\(V_{O_2}=\dfrac{3}{35}.24,79\approx2,1249\left(l\right)\)
\(m_{KCl}=\dfrac{2}{35}.74,5\approx4,257\left(g\right)\)
\(H=\dfrac{2,98}{4,257}.100\%=70\%\)
`#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, PT: \(2KClO_3\underrightarrow{t^o}2KCl+3O_2\)
Ta có: \(n_{KCl}=\dfrac{1,49}{74,5}=0,02\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{3}{2}n_{KCl}=0,03\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,03.24,79=0,7437\left(l\right)\)
b, Theo PT: \(n_{KClO_3\left(TT\right)}=n_{KCl}=0,02\left(mol\right)\)
\(\Rightarrow m_{KClO_3\left(TT\right)}=0,02.122,5=2,45\left(g\right)\)
\(\Rightarrow H=\dfrac{2,45}{3,5}.100\%=70\%\)
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: \(\left\{{}\begin{matrix}n_{CO_2}=\dfrac{1}{2}n_{O_2}=0,05\left(mol\right)\\n_{H_2O}=n_{O_2}=0,1\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow V_{CO_2}=0,05.24,79=1,2395\left(l\right)\)
\(m_{H_2O}=0,1.18=1,8\left(g\right)\)
Bài 15:
a) \(n_{O_2}=\dfrac{12,395}{24,79}=0,5\left(mol\right)\)
PTHH: 2H2O --đp--> 2H2 + O2
1<--------------0,5
=> \(H=\dfrac{1.18}{22,5}.100\%=80\%\)
b) \(n_{H_2O}=\dfrac{81}{18}=4,5\left(mol\right)\)
PTHH: 2H2 + O2 --to--> 2H2O
4,5<------------4,5
=> \(V_{H_2\left(lý.thuyết\right)}=4,5.24,79=111,555\left(l\right)\)
=> \(V_{H_2\left(tt\right)}=\dfrac{111,555.100}{90}=123,95\left(l\right)\)
c) \(n_{H_2}=\dfrac{30,9875}{24,79}=1,25\left(mol\right)\)
PTHH: 2H2O --đp--> 2H2 + O2
1,25<-------1,25
=> \(m_{H_2O\left(lý.thuyết\right)}=1,25.18=22,5\left(g\right)\)
=> \(m_{H_2O\left(tt\right)}=\dfrac{22,5.100}{75}=30\left(g\right)\)
\(n_{H_2O}=\dfrac{22,5}{18}=1,25\left(mol\right)\)
\(n_{O_2}=\dfrac{12,395}{24,79}=0,5mol\)
\(2H_2O\rightarrow\left(điện.phân\right)2H_2+O_2\)
1,25 0,5 ( mol ) ( thực tế )
1 0,5 ( mol ) ( lý thuyết )
\(H=\dfrac{1}{1,25}.100=80\%\)
b.\(n_{H_2O}=\dfrac{81}{18}=4,5\left(mol\right)\)
\(2H_2+O_2\rightarrow\left(t^o\right)2H_2O\)
4,5 4,5 ( mol )
\(V_{H_2}=4,5.24,79:90\%=123,95l\)
c.\(n_{H_2}=\dfrac{30,9875}{24,79}=1,25mol\)
\(2H_2O\rightarrow\left(điện.phân\right)2H_2+O_2\)
1,25 1,25 ( mol )
\(m_{H_2O}=1,25.18:75\%=30g\)
a, \(2KClO_3\underrightarrow{t^o}2KCl+3O_2\)
b, \(n_{KCl}=\dfrac{0,745}{74,5}=0,01\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{3}{2}n_{KCl}=0,015\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,015.24,79=0,37185\left(l\right)\)
\(m_{O_2}=0,015.32=0,48\left(g\right)\)
c, \(n_{KClO_3\left(pư\right)}=n_{KCl}=0,01\left(mol\right)\)
\(\Rightarrow m_{KClO_3\left(pư\right)}=0,01.122,5=1,225\left(g\right)\)
\(\Rightarrow H=\dfrac{1,225}{2,5}.100\%=49\%\)