Question

Remember to explain and show work.

26. How much heat will be absorbed if 45.0 g of C react with excess water?

27. How much heat is released when 9.22 grams of glucose C6H12O6 in your body reacts with according to the following equation?​

Answer 1

26. 42.3 kJ; 27. 143 kJ

Explanation:

26. Formation of water gas

We know that we will need the balanced equation with masses, molar masses, and enthalpies, so let’s gather all the information in one place.

A_r: 12.01

C + H₂O ⟶ CO + H₂; ΔH_r = +113 kJ

Mass/g: 4.50

(a) Calculate the moles of C

Moles of C = 4.50 × 1/12.01 = 0.375 mol C

(b) Calculate the energy absorbed

The conversion factor is 113 kJ/1 mol Al

Heat = 0.375 × 113/1 = 42.3 kJ

27. Oxidation of glucose

A_r: 180.16

C₆H₁₂O₆ + 6O₂ ⟶ 6CO₂ + 6H₂O; ΔH_r = -2803 kJ

Mass/g: 9.22

(a) Calculate the moles of C₆H₁₂O₆

Moles of C₆H₁₂O₆ = 9.22 × 1/180.16 = 0.051 07 mol C₆H₁₂O₆

(b) Calculate the energy absorbed

The conversion factor is (-2803 kJ/1 mol C₆H₁₂O₆)

Heat = 0.051 07 × (-2803)/1 = -143 kJ

The oxidation of glucose releases 143 kJ .