1)

дано

V(CO2) = 448 L

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m(C2H6)-?

2C2H6+7O2-->4CO2+6H2O

n(CO2) = V(CO2) / Vm = 448 / 22.4 =  20 mol

2nC2H6 = 4nCO2

n(C2H6) = 2*20 / 4 = 10 mol

M(C2H6) =30 g/mol

m(C2H6) = n*M = 10*30 = 300 g

ответ 300 г

2)

дано

V(O2) = 112 L

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m(C3H8)-?

C3Н8+5O2-->3CO2+4H2O

n(O2) = V(O2) / Vm = 112 / 22.4 =  5 mol

nC3H8 = 5nO2

n(C3H8) = 5*1 / 5 = 1 mol

M(C3H8) =44 g/mol

m(C3H8) = n*M = 1*44 = 44 g

ответ 44 г

3)

дано

V(CO2) = 44.8 L

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m(C4H10)-?

2C4H10+13O2-->8CO2+10H2O

n(CO2) = V(CO2) / Vm = 44.8 / 22.4 =  2 mol

2nC4H10 = 8nCO2

n(C4H10) = 2*2 / 8 = 0.5 mol

M(C4H10) =58 g/mol

m(C4H10) = n*M = 0.5*58 = 29 g

ответ 29 г

4)

дано

V(O2) = 11.2 L

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m(CH4)-?

CH4+2O2-->CO2+2H2O

n(O2) = V(O2) / Vm = 11.2  / 22.4 = 0.5  mol

nCH4 = 2nO2

n(C4H10) = 1*0.5 / 2 = 0.25 mol

M(CH4) =58 g/mol

m(CH4) = n*M = 0.25*58 = 14.5 g

ответ 14.5 г

5)

дано

V(O2) = 22.4 L

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m(C6H14)-?

2C6H14+19O2-->12CO2+14H2O

n(O2) = V(O2) / Vm = 22.4 / 22.4 =  1 mol

2nC6H14 = 19nCO2

n(C6H14) = 1*2 / 19 = 0.11  mol

M(C6H14) =86 g/mol

m(C4H10) = n*M = 0.11 *86 = 9.46 g

ответ 9.46  г