How much energy must be removed from a 125 g sample of benzene (CHo) vapor at 42
ID: 1034218 • Letter: H
Question
How much energy must be removed from a 125 g sample of benzene (CHo) vapor at 425.0 K to make it a solid at 200.0 K? Use the following steps to get to your answer. You MUST show your work to receive any credit. The following physical data for benzene may be useful. See announcement for due date. AHvap 33.9 kJ/mol Cliq 1.73 J/g C Tmelting-279.0 K AHfus* 9.8 kJ/mol Cgas-1.06 J/g C Tbong 353.0K Csol. 1.51 J/g°C 1) Determine number of moles the sample contains moles 2) How much energy must be removed to cool the gas to its boiling point? How mach energy mst be removed to convert the gas to a liqi How much energy mst be removed to being the liquid from ib boiling point lo its melting point? How much energy mast be remood to convert the liquid to a soliaExplanation / Answer
Q = m * c * dT
Q = m * cgas * dT + m/molar mass * dH vap + m * Cliquid * dT + m/molar mass * dH fus + m * Csol * dT
Q = 125 * 1.06 * (353 - 425) + 125/78 * 33.9 *10^3 + 125 * 1.73 *(279 - 353) + 125/78 * 9.8 * 10^3 + 125 * 1.51 * (200 -279)
Q = 29578.3 J
1)
Number of moles of the sample = 125/78 = 1.6025 moles
2)
Q = m * cgas * dT + m/molar mass * dH vap
Q = 125 * 1.06 * (353 - 425) + 125/78 * 33.9 *10^3
Q = 44786.9 J
3)
Q = m * cgas * dT + m/molar mass * dH vap + m * Cliquid * dT + m/molar mass * dH fus
Q = 125 * 1.06 * (353 - 425) + 125/78 * 33.9 *10^3 + 125 * 1.73 *(279 - 353) + 125/78 * 9.8 * 10^3
Q = 44489.55 J
4)
Q = m * Cliquid * dT + m/molar mass * dH fus
Q = 125 * 1.73 *(279 - 353) + 125/78 * 9.8 * 10^3
Q = -297.37 J
5)
Q = m * Cliquid * dT + m/molar mass * dH fus + m * Csol * dT
Q = 125 * 1.73 *(279 - 353) + 125/78 * 9.8 * 10^3 + 125 * 1.51 * (200 -279)
Q = -15208.62 J
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.