Question

"In the absence of an adequate supply of oxygen, yeasts obtains metabolic energy by fermentation of glucose to produce ethanol. C6H12O6(s) LaTeX: \longrightarrow⟶ 2 C2H5OH(l) + 2 CO2(g) Use the standard enthalpies of formation to calculate ΔH for this reaction" Substance ΔHo glucose(s) -304.5 kcal/mol CO2(g) -93.9 kcal/mol C2H5OH(l) -66.4 kcal/mol

Answer 1

Answer:
`\Delta H=-16.5 kcal`

Step-by-step explanation:

The balanced chemical reaction is,

`C_6H_(12)O_6(s)\longrightarrow 2C_2H_5OH(l)+2CO_2(g)`

The expression for enthalpy change is,

`\Delta H=\sum [n* \Delta H_f(product)]-\sum [n* \Delta H_f(reactant)]`

`\Delta H=[(n_(C_2H_5OH)* \Delta H_(C_2H_5OH))+(n_(CO_2)* \Delta H_(CO_2))]-[(n_{C_6H_(12)O_6}* \Delta H_{C_6H_(12)O_6})]`

where,

n = number of moles

Now put all the given values in this expression, we get

`\Delta H=[(2* -66.4)+(2* -93.9)]-[(1* -304.5)]`

`\Delta H=-16.5kcal`

Therefore, the enthalpy change for this reaction is -16.5 kcal