Question

19. Which of the following chemical equations represents

propane combusts?
A. 2 CsHe (g) + 5O2 (g) → 3C02(g) + 4H20 (1)
B. 2 CsHe (g) + 5O2 (g) → 3CO2(g) + 3H20(1
C. CsHe (g) + O2 (g) → CO2(g) + H2O(1)
D. CsHa (g) + 5O2 (g) → 3CO2(g) + 4H2O(1)

Answer 1

• C₃H₈ (g) + 5O₂(g) → 3CO₂ (g) + 4H₂O (l)

(option D. with the proviso that the subscripts of propane's chemical formula must be corrected)

Step-by-step explanation:

Propane is the saturated hydrocarbon, alkane, with chemical formula C₃H₈ or CH₃CH₂CH₃.

The complete combustion of the hydrocarbons yield carbon dioxide (CO₂) and water (H₂O).

The chemical equation that represents this combustion is:

• C₃H₈ (g) + O₂(g) → CO₂ (g) + H₂O (l) (skeleton equation: unbalanced)

Once you balance it, you get:

• C₃H₈ (g) + 5O₂(g) → 3CO₂ (g) + 4H₂O (l)

Left side Right side

C 3 3

H 8 4×2 = 8

O 5×2 = 10 3×2 + 4 = 10

That equation corresponds to the option D. of the list, with the proviso that the subscripts of propane's chemical formula must be corrected