Aliquid sample that weighs 2.585 g is a mixture of butane (c4h10) and hexane (c6h14). when the sample is combusted in an excess of oxygen, 3.929 g of water are formed.

Missing question: How much butane and hexane (answer in g) were in the original sample?

Answer is: 1.138 grams of butane and 2.61 grams hexane.

Balanced chemical reactions:

1) C₄H₁₀ + 13/2O₂ → 4CO₂ + 5H₂O.

2) C₆H₁₄ + 19/2O₂ → 6CO₂ + 7H₂O.

m(H₂O) = 3.929 g.

n(H₂O) = 3.929 g ÷ 18 g/mol.

n(H₂O) = 0.218 mol.

Amount of water in both reactions is 0.218 mol, five parts from butane, seven parts from hexane.

n(H₂O) = (0.218 mol ÷ 12) · 5 = 0.091 mol; water from butane.

n(C₄H₁₀) : n(H₂O) = 1 : 4.

n(C₄H₁₀) = 0.023 mol.

m(C₄H₁₀) = 0.023 mol · 58 g/mol = 1.318 g.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).