Question

Glucose, also known as "blood sugar," has the formula C6H12O6.

Write the equation for the combustion of glucose with O2 to give CO2 and H2O. (Use the lowest possible coefficients.)

C6H12O6 + O2 CO2 + H2O

If 3.8 kcal is released by combustion of each gram of glucose, how many kilocalories are released by the combustion of 1.35 mol of glucose?

What is the minimum amount of energy a plant must absorb to produce 13.5 g of glucose?

Answer 1

balanced equation : C6H12O6 + 6 O2 -----------------------> 6 CO2 + 6 H2O

C6H12O6 + 6 O2 -----------------------> 6 CO2 + 6 H2O

moles of glucose = 1.35

mass of glucose = moles x molar mass

                           = 1.35 x 180

                            = 243 g

1 g glucose gives ----------------------------> 3.8 kcal

243 g glucose gives -----------------------> 3.8 x 243 kcal = 923.4 kcal

energy released for 1.35 moles glucose = 923.4 kcal

1 g glucose -------------------------> 3.8 kcal

13.5 g glucose ---------------------> 13.5 x 3.8 = 51.3 kcal

51.3 kcal amount energy absorbed by plant