Pentaborane B₅H₉(s) Burns Vigorously in O₂ to Give B₂O₃(s) and H₂O(l)

question 110

Multiple Choice

Pentaborane B₅H₉(s) burns vigorously in O₂ to give B₂O₃(s) and H₂O(l) . What is ΔH° for the combustion of 1 mol of B₅H₉(s) ? Substance ΔH°_f (kJ/mol)
B₂O₃(s) -1273.5
B₅H₉(s) +73.2
H₂O(l) -285.8

• A) -1486.1 kJ
• B) -1632.5 kJ
• C) -4396.7 kJ
• D) -4652.85 kJ
• E) -9086.1 kJ

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Definitions:

Natural Cements

Substances that occur in nature, which can act to bind materials together through a chemical or physical process.

Clasts

Fragments of rocks or minerals that are embedded in a larger rock matrix, often found in sedimentary rocks.

Dissolved Materials

Substances that are incorporated into a liquid, forming a solution without altering their chemical composition.

Clastic Sedimentary Rocks

Rocks formed from the accumulation and lithification of mechanical weathering debris.