An experiment produces evidence that the evaporation of 4.00 g of liquid butane C4H10 (l) requires a gain in enthalpy of 1.67 kJ. Find the molar enthalpy of vaporization in kJ/mol for butane from this evidence.

Question

Chemistry

Caitlyn Liu

20 July, 09:06

An experiment produces evidence that the evaporation of 4.00 g of liquid butane C4H10 (l) requires a gain in enthalpy of 1.67 kJ. Find the molar enthalpy of vaporization in kJ/mol for butane from this evidence.

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Answers (1)

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Braylon · Answer 1

The molar enthalpy of vaporization in kJ/mol for butane = 24.265 kJ/mol.

Explanation:

Firstly, we need to calculate the no. of moles of 4.00 g of liquid butane C₄H₁₀:

n = mass/molar mass = (4.0 g) / (58.12 g/mol) = 0.0688 mol.

∴ 0.0688 mol of butane requires a gain in enthalpy of 1.67 kJ to be evaporized.

Know using cross multiplication:

0.0688 mol of butane to be vaporized requires → 1.67 kJ.

1.0 mol of butane to be vaporized requires →? kJ.

∴ 1.0 mol of butane to be vaporized requires = (1.0 mol) (1.67 kJ) / (0.0688 mol) = 24.265 kJ.

∴ The molar enthalpy of vaporization in kJ/mol for butane = 24.265 kJ/mol.