Question

Combustion of ethane gas is an exothermic reaction. Which of the following best describes the temperature conditions that are likely to make the combustion of ethane gas a spontaneous change? (4 points) Any temperature, because combustion of ethane leads to an increase in entropy. Any temperature, because combustion of ethane leads to a decrease in entropy. Low temperature only, because combustion of ethane leads to an increase in entropy. High temperature only, because combustion of ethane leads to a decrease in entropy.

Answer 1

Any temperature, because combustion of ethane leads to an increase in entropy.

Step-by-step explanation:

2C₂H₆(g) + 7O₂(g) ⟶ 4CO₂(g) + 6H₂O(g); ΔH <0

Δn(gas) = 10 - 9. so

ΔS > 0

The requirement for spontaneity is that

ΔG = ΔH - TΔS < 0

ΔH is negative.

ΔS positive, so TΔS is positive.

ΔG = (a negative term) - (a positive term) = a negative term

ΔG is always negative, so the reaction is always spontaneous.

B is wrong, because ΔS is positive.

C and D are wrong, because the reaction is always spontaneous.