Question

Question 4

Part A

Using the following equation for the combustion of octane, calculate the heat of reaction for 100.0 g of octane. The molar mass of octane is 114.33 g/mole.

2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O ΔH°_rxn = -11018 kJ

Using the following equation for the combustion of octane, calculate the heat of reaction for 100.0 g of octane. The molar mass of octane is 114.33 g/mole.

2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O ΔH°_rxn = -11018 kJ

-4.82 x 10³ kJ

-9.64 x 10³ kJ

-1.26 x 10⁴ kJ

-4.82 kJ

Answer 1

answer : ΔH°rxn = - 4.82 x 10^3 kJ

2 C₈H₁₈ + 25 O₂ ---------------> 16 CO₂ + 18 H₂O                        ΔH°_rxn = -11018 kJ

moles of octane = 100 / 114.33 = 0.875 mol

2 mol octane   --------------->    ΔH°_rxn = -11018 kJ

0.875 mol octane   ------------------>   ??

   ΔH°_rxn   = 0.875 x - 11018 / 2

ΔH°rxn = - 4.82 x 10^3 kJ