contestada

If 8.2 g of sodium ethanoate produced 560 cm3 of methane (at s.t.p.). which one of the following is the percentage yield of the reaction;
A 2.5
B 4.0
C 12.0
D 25.0

Respuesta :

The percentage yield of the reaction : 25%

Further explanation

C₂H₃NaO₂(CH₃COONa)- Sodium ethanoate(MW=82,0343 g/mol)

Reaction

CH₃COONa + NaOH⇒CH₄+Na₂CO₃

mol CH₃COONa :

[tex]\tt \dfrac{8.2}{82.0343}=0.1[/tex]

mol CH₄=mol CH₃COONa = 0.1

mass CH₄ (MW=16.04 g/mol) :

[tex]\tt 0.1\times 16.04=1.604~g[/tex]⇒ theoretical

mol of 560 cm³(0.56 L) of methane (⇒1 mol = 22.4 L at STP) :

[tex]\tt \dfrac{0.56}{22.4}=0.025~mol[/tex]

mass  CH₄ :

[tex]\tt 0.025\times 16.04=0.401~g[/tex]

[tex]\tt \%yield=\dfrac{0.401}{1.604}\times 100\%=25\%[/tex]