what is the magnitude and sign of the molar heat of vaporization of butane
22.44 kJ/mol according to this page.
http://en.wikipedia.org/wiki/Butane_%28data_page%29#Thermodynamic_properties
The molar heat of vaporization, denoted as ΔHvap, represents the amount of heat energy required to vaporize one mole of a substance at its boiling point.
The molar heat of vaporization of butane, C4H10, is approximately 22.44 kJ/mol at its boiling point of -0.5 degrees Celsius.
In terms of the sign, the molar heat of vaporization is a positive value as heat is absorbed during the vaporization process.
Therefore, the magnitude of the molar heat of vaporization of butane is approximately 22.44 kJ/mol and its sign is positive.
To find the magnitude and sign of the molar heat of vaporization of butane, you can refer to reliable sources such as scientific literature, textbooks, or chemical databases. However, as an AI text-based model, I don't have real-time access to specific values. Nonetheless, I can guide you on how to find this information.
1. Check scientific literature: Search for research papers or scholarly articles related to butane's molar heat of vaporization. Journals like the Journal of Chemical Thermodynamics or Chemical Engineering Science often contain such data.
2. Consult textbooks: Look for chemistry or thermodynamics textbooks that cover the topic of phase changes and heat of vaporization. Many textbooks provide tables or graphs with common chemical properties, including heat of vaporization values.
3. Chemical databases: Access reputable chemical databases such as NIST Chemistry WebBook, CRC Handbook of Chemistry and Physics, or PubChem. These databases compile vast amounts of chemical data, including the molar heat of vaporization for different substances.
By referring to these sources, you should be able to find the magnitude (numerical value) and the sign (whether it is positive or negative) of the molar heat of vaporization of butane.