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Which of the following is a correctly written thermochemical equation?

2C8H18 +25O2 → 16CO2 + 18H2O, ΔH = –5,471 kJ/mol


Correct Answer

C5H12 (g) + 8O2 (g) → 5CO2 (g) + 6H2O (l), ΔH = –3,536.1 kJ/mol


Incorrect Response

C3H8 (g) + O2 (g) → CO2 (g) + H2O (l), ΔH = –2,220 kJ/mol

Which of the following is a correctly written thermochemical equation? 2C8H18 +25O-example-1

2 Answers

0 votes
The correct answer is:

C5H12 (g) + 8O2 (g) → 5CO2 (g) + 6H2O (l), ΔH = –3,536.1 kJ/mol

Step-by-step explanation:

The correctly written thermochemical equation should include the balanced chemical equation and the corresponding enthalpy change (ΔH). The balanced chemical equation must have equal numbers of atoms on both sides of the equation, and the state of each substance should be indicated. The enthalpy change should be written with the correct sign (positive or negative) and unit (kJ/mol).

The first equation is correctly balanced, but the enthalpy change is not correct. The correct enthalpy change for this reaction is –5,471 kJ/mol, but it is written as a positive value in the equation. The correct enthalpy change should be written as ΔH = –5,471 kJ/mol.

The second equation is correctly balanced and includes the correct enthalpy change (ΔH = –3,536.1 kJ/mol). Therefore, it is the correctly written thermochemical equation
User Mingaleg
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2 votes

Answer:

The second option

Step-by-step explanation:

User Bossie
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