Bài 1: Đốt cháy 4,48 lít CH4(đktc) trong O2 thu được CO2 và H2O

a)Tính mH2O thu được

b)Tính VO2(đktc) cần dùng

c)Tính mCO2 thu được (định luật bảo toàn khối lượng)

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nCH4=4,48/22,4=0,2(mol)

a) PTHH: CH4 + 2 O2 -to-> CO2 + 2 H2O

0,2________0,4______0,2_____0,4(mol)

mH2O=0,4.18=7,2(g)

b) V(O2,đktc)=0,4.22,4=8,96(l)

c) Theo ĐLBTKL:

mCH4+ mO2= mCO2+ mH2O

<=> 0,2.16 + 0,4.32= mCO2 + 7,2

<=> mCO2=8,8(g)

Bài 2:

a) nP2O5= 71/142=0,5(mol)

PTHH: 4 P + 5 O2 -to-> 2 P2O5

Ta có: nO2= 5/2. nP2O5= 5/2. 0,5= 1,25(mol)

=> V(O2,đktc)=1,25.22,4=28(l)

b) Theo ĐLBTK, ta có:

mP + mO2= mP2O5

<=> mP + 1,25. 32= 71

<=> mP= 31(g)

\(n_P=\dfrac{3.1}{31}=0.1\left(mol\right)\)

\(4P+5O_2\underrightarrow{^{^{t^0}}}2P_2O_5\)

\(0.1.......0.125.....0.05\)

\(V_{O_2}=0.125\cdot22.4=2.8\left(l\right)\)

\(m_{P_2O_5}=0.05\cdot142=7.1\left(g\right)\)

n_P= 3,1 / 31 =0,1 mol

          2P +   5/2O₂ → P₂O₅

           0,1     0,125       0,05      mol

V_O2=0,125.22,4=2,8 l

b) mP₂O₅=0,05.142=7,1 g

a, PT: \(S+O_2\underrightarrow{t^o}SO_2\)

\(4P+5O_2\underrightarrow{t^o}2P_2O_5\)

b, Ta có: \(n_{SO_2}=\dfrac{2,479}{24,79}=0,1\left(mol\right)\)

Theo PT: \(n_S=n_{SO_2}=0,1\left(mol\right)\)

⇒ m_P = 6,3 - m_S = 6,3 - 0,1.32 = 3,1 (g)

\(\Rightarrow n_P=\dfrac{3,1}{31}=0,1\left(mol\right)\)

Theo PT: \(n_{O_2}=n_S+\dfrac{5}{4}n_P=0,225\left(mol\right)\)

\(\Rightarrow V_{O_2}=0,225.24,79=5,57775\left(l\right)\)

c, Theo PT: \(n_{P_2O_5}=\dfrac{1}{2}n_P=0,05\left(mol\right)\)

\(\Rightarrow m_{P_2O_5}=0,05.142=7,1\left(g\right)\)

a)

\(4P + 5O_2 \xrightarrow{t^o} 2P_2O_5\)

b)

Ta có : \(n_P = \dfrac{3,1}{31} = 0,1(mol)\)

Theo PTHH : 

\(n_{P_2O_5} = 0,5n_P = 0,05(mol)\\ n_{O_2} = \dfrac{5}{4}n_P = 0,125(mol)\)

Suy ra : 

\(m_{P_2O_5} = 0,05.142 = 7,1(gam)\\ V_{O_2} = 0,125.22,4 = 2,8(lít)\)

a) PTHH: \(4P+5O_2\underrightarrow{t^o}2P_2O_5\)

b) Ta có: \(n_P=\dfrac{3,1}{31}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{O_2}=0,125mol\\n_P=0,05mol\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{P_2O_5}=0,05\cdot142=7,1\left(g\right)\\V_{O_2}=0,125\cdot22,4=2,8\left(l\right)\end{matrix}\right.\)

1. PTHH: 4P + 5O₂  2P₂O₅

2. 

Từ PT  nO2=0,125(mol);nP2O5=0,05(mol)

đktc: VO2=0,125.22,4=2,8(l)

3. mP2O5=0,05.142=7,1(g)

a) 4P + 5O₂ --t^o--> 2P₂O₅

b) \(n_P=\dfrac{3,1}{31}=0,1\left(mol\right)\)

PTHH: 4P + 5O₂ --t^o--> 2P₂O₅

_____0,1-->0,125---->0,05

=> m_P2O5 = 0,05.142 = 7,1 (g)

c) V_O2 = 0,125.22,4 = 2,8(l)

a) 4P + 5O₂ --t^o--> 2P₂O₅

b)0,1mol

c, 2,8l

a. \(n_P=\dfrac{3.1}{31}=0,1\left(mol\right)\)

PTHH : 4P + 5O₂ ---t^o----> 2P₂O₅

             0,1     0,125           0,05

b. \(m_{P_2O_5}=0,05.142=7,1\left(g\right)\)

c. \(V_{O_2}=0,125.22,4=2,8\left(l\right)\\ \Rightarrow V_{kk}=2,8.5=14\left(l\right)\)

4P+5O2-to>2P2O5

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

n P=\(\dfrac{3,1}{31}\)=0,1 mol

=>Vkk=0,125.22,4.5=14l

=>m P2O5=0,05.142=7,1g

TK

a. n P = 3.1 31 = 0 , 1 ( m o l ) PTHH : 4P + 5O2 ---to----> 2P2O5 0,1 0,125 0,05 b. m P 2 O 5 = 0 , 05.142 = 7 , 1 ( g ) c. V O 2 = 0 , 125.22 , 4 = 2 , 8 ( l ) ⇒ V k k = 2 , 8.5 = 14 ( l )

a) C + O₂ --t^o--> CO₂

b) \(n_C=\dfrac{24}{12}=2\left(mol\right)\)

=> n_CO2 =2 (mol)

=> m_CO2 = 2.44 = 88(g)

c)

n_O2 = 2(mol)

=> V_O2 = 2.22,4 = 44,8 (l)

=> V_kk = 44,8.5=224(l)

a)

$C + O_2 \xrightarrow{t^o} CO_2$
b)

$n_{CO_2} = n_C = \dfrac{24}{12} = 2(mol)$
$m_{CO_2} = 2.44 = 88(gam)$
c)

$n_{O_2} = n_C = 2(mol)$
$V_{O_2} = 2.22,4 = 44,8(lít)$
$V_{không\ khí} =5 V_{O_2} = 44,8.5 = 224(lít)$

a: \(C+O_2\rightarrow CO_2\)

b: \(n_C=\dfrac{24}{12}=2\left(mol\right)\)

\(\Leftrightarrow n_{CO_2}=2\left(mol\right)\)

\(\Leftrightarrow m_{CO_2}=2\cdot44=88\left(g\right)\)

nCu = 6,4/64 = 0,1 (mol)

PTHH: 2Cu + O2 -> (t°) 2CuO

Mol: 0,1 ---> 0,05 ---> 0,1

mCuO = 0,1 . 80 = 8 (g)

Vkk = 0,05 . 5 . 22,4 = 5,6 (l)

Bài 1:

\(n_{O_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

\(4P+5O_2\rightarrow2P_2O_5\)

0,24.... 0,3 .... 0,12 (mol)

\(m_P=0,24.31=7,44\left(g\right)\)

\(m_{P_2O_5}=0,12.142=17,04\left(g\right)\)

Bài 2:

\(n_{Al}=\dfrac{21,6}{27}=0,8\left(mol\right)\)

\(4Al+3O_2\rightarrow2Al_2O_3\)

0,8 .... 0,6 ...... 0,4 (mol) 

\(m_{Al_2O_3}=0,4.102=40,8\left(g\right)\)

\(V_{O_2}=0,6.22,4=13,44\left(l\right)\)