V(O2)= 20%.Vkk=20%. 44,8= 8,92(l) => nO2=0,4(mol)

nC3H8= 1,344/22,4= 0,06(mol)

PTHH: C3H8 +  5 O2 -to-> 3 CO2 + 4 H2O

Ta có: 0,06/1 < 0,4/5

=> O2 dư, C3H8 hết, tính theo nC3H8

=> nO2(p.ứ)= 0,06.5=0,3(mol)=> nO2(dư)=0,4-0,3=0,1(mol)

=> V(O2,dư)=0,1.22,4=2,24(l)

b) nCO2=3.0,06=0,18(mol)

=>mCO2=0,18 . 44=7,92(g)

nH2O=0,06.4=0,24(mol)

=>mH2O=0,24.18=4,32g)

Chúc em học tốt!

\(n_{C_2H_4}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\\ PTHH:C_2H_4+3O_2\rightarrow\left(t^o\right)2CO_2+2H_2O\\ n_{O_2}=3.0,4=1,2\left(mol\right);n_{CO_2}=0,4.2=0,8\left(mol\right)\\ a,V_{O_2\left(đktc\right)}=22,4.1,2=26,88\left(l\right)\\ b,V_{kk\left(đktc\right)}=\dfrac{100}{20}.26,88=134,4\left(l\right)\\ c,CO_2+Ca\left(OH\right)_2\rightarrow CaCO_3\downarrow\left(trắng\right)+H_2O\\ n_{CaCO_3}=n_{CO_2}=0,8\left(mol\right)\\ m_{kết.tủa}=m_{CaCO_3}=100.0,8=80\left(g\right)\)

PT: \(CH_4+2O_2\underrightarrow{t^o}CO_2+2H_2O\)

Ta có: \(n_{CH_4}=\dfrac{30,9875}{24,79}=1,25\left(mol\right)\)

a, \(n_{H_2O}=2n_{CH_4}=2,5\left(mol\right)\) \(\Rightarrow m_{H_2O}=2,5.18=45\left(g\right)\)

b, \(n_{O_2}=2n_{CH_4}=2,5\left(mol\right)\) \(\Rightarrow V_{O_2}=2,5.24,79=61,975\left(l\right)\)

Mà: O₂ chiếm 1/5 thể tích không khí.

\(\Rightarrow V_{kk}=5V_{O_2}=309,875\left(l\right)\)

C₂H₂+\(\dfrac{5}{2}\)O₂-to>2CO₂+H₂O

0,05--0,125---------0,1 mol

n _C2H2=\(\dfrac{1,12}{22,4}\)=0,05 mol

=>m _CO2=0,1.44=4,4g

=>Vkk=0,125.5.22,4=5,6l

CH4+2O2-to>CO2+2H2O

0,2-----0,4------0,2

n CH4=0,2 mol

=>mCO2=0,2.44=8,8g

=>VO2=0,4.22,4=8,96l

=>Vkk=8,96.5=44,8l

nCH4 = 4,48:22,4 = 0,2 (mol)
pthh : CH4 + 2O2 -t-> CO2 + 2H2O 
        0,2        0,4         0,2 
mCO2 = 0,2 . 44 = 8,8 (G) 
V_O2   = 0,4 . 22,4 = 8,96 (L) 
=> V_kk = VO2 : 20% = 8,96 : 20% = 44,8 (L) 

\(n_{C_2H_4}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\)

C₂H₄ + 3O₂ ----t^o---> 2CO₂ + 2H₂O

0,4        1,2                                0,8

\(m_{H_2O}=0,8.18=14,4\left(g\right)\)

\(V_{kk}=5V_{O_2}=5.1,2.22,4=134,4\left(l\right)\)

Theo gt ta có: $n_{H_2}=0,75(mol)$

a, $2H_2+O_2\rightarrow 2H_2O$

Ta có: $n_{O_2}=0,5.n_{H_2}=0,375(mol)\Rightarrow V_{O_2}=8,4(l)\Rightarrow V_{kk}=42(l)$

b, $2KMnO_4\rightarrow K_2MnO_4+MnO_2+O_2$

Ta có: $n_{KMnO_4}=2.n_{O_2}=0,75(mol)\Rightarrow m_{KMnO_4}=118,5(g)$

a)

\(2H_2 + O_2 \xrightarrow{t^o} 2H_2O\\ V_{O_2} = \dfrac{V_{H_2}}{2} = \dfrac{16,8}{2} = 8,4(lít)\\ V_{không\ khí} = \dfrac{8,4}{20\%} = 42(lít)\)

b)

\(n_{O_2} = \dfrac{8,4}{22,4} = 0,375(mol)\\ 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ n_{KMnO_4} = 2n_{O_2} = 0,75(mol)\\ \Rightarrow m_{KMnO_4} = 0,75.158 = 118,5(gam)\\ 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ n_{KClO_3} = \dfrac{2}{3}n_{O_2} = 0,25(mol)\\ \Rightarrow m_{KClO_3} = 0,25.122,5 = 30,625(gam)\)

\(n_{H_2}=\dfrac{16.8}{22.4}=0.75\left(mol\right)\)

\(2H_2+O_2\underrightarrow{t^0}2H_2O\)

\(0.75...0.375\)

\(V_{O_2}=0.375\cdot22.4=8.4\left(l\right)\)

\(V_{kk}=5V_{O_2}=8.4\cdot5=42\left(l\right)\)

\(2KMnO_4\underrightarrow{t^0}K_2MnO_4+MnO_2+O_2\)

\(0.75..............................................0.375\)

\(m_{KMnO_4}=0.75\cdot158=118.5\left(g\right)\)

\(2KClO_3\underrightarrow{t^0}2KCl+3O_2\)

\(0.25.......................0.375\)

\(m_{KClO_3}=0.25\cdot122.5=30.625\left(g\right)\)

a. \(n_{CH_4}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

PTHH : CH₄ + 2O₂ -> CO₂ + 2H₂O

             0,2        0,4                  ( mol )

\(V_{O_2}=0,4.22,4=8,96\left(l\right)\)

b. \(V_{kk}=8,96.5=44,8\left(l\right)\)

2H2+O2-to>2H2O

0,1----0,05----0,1

n H2=0,1 mol

=>m H2OI=0,1.18=1,8g

=>Vkk=0,05.22,4.5=5,6l