Respuesta :
In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH₃CH₂OH and CO₂. During cellular respiration (combustion), sugar and ethanol yield water vapor and CO₂.
a) ΔH rxn (fermentation) = -2816 kJ/mol
ΔH rxn (respiration) = -1409,2kJ/mol
The fermentation of sugar is given as follows:
C₆H₁₂O₆ (s) + 6O₂ (g) → 6O₂ (g) + 6H₂O (l)
ΔHrxn = ΔHformation (products) - ΔHformation (reactants
[tex]=(6 mol* - 393.5 kJ/mol) + (6mol* -285.8kJ/mol)- (1mol *-1260kJ/mol+6mol*0 )[/tex]
= -2816 kJ/mol
The heat of combustion of ethanol is given as follows:
C₂H₅OH (l) + 3O₂ (g) → 3H₂O(g) + 2CO₂(g)
Let's assume that 1 mole of ethanol is burnt. The heat of reaction, ΔHrxn is given by:
ΔHrxn = ΔHformation (products) - ΔHformation (reactants)
[tex]= (2mol*-393kJ/mol)+ (3mol*-285.8kJ/mol)- [(1mol * -235kJ/mol)+(3mol* 0,0000kJ)][/tex]
[tex]= -1644-(-235.2)\\= -1409.2kJ/mol[/tex]
To know more about fermentation refer to: https://brainly.com/question/13050729
#SPJ4
