Question

The complete combustion of 1.00 mol of table sugar, C₁₂H₂₂O₁₁, yields 5.65 x 10³ kJ. The average Canadian currently consumes approximately 40 kg of sugar a year, far in excess of the WHO recommendation of about 10 kg of sugar annually. Determine the amount of EXCESS energy we are getting from the sugar in our diets.

Answer 1

We have given,

1.00 mol of table sugar = 5.66 x 10³ kJ

Also given,

The amount of sugar the average Canadian currently consumes = 40 Kg

WHO recommendation of consumption of sugar = 10 Kg

So, the Excess amount of sugar consumed = 40 kg - 10 Kg = 30 Kg

Now, Converting 30 Kg of C₁₂H₂₂O₁₁ to the number of moles,

= 30 Kg x ( 1000g /1 Kg) x (1 mole /342.3 g)

= 87.64 moles of table sugar (C₁₂H₂₂O₁₁)

Thus, the excess energy will be,

= 87.64 moles of C₁₂H₂₂O₁₁ x (5.66 x 10³ kJ / 1 mole )

= 4.96 x 10⁵ kJ of excess energy

Thus, 4.96 x 10⁵ kJ of excess energy we are getting from the sugar in our diets.