Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

..ooo Sprint 2:37 PM 100% session.masteringchemistry.com C Inquiry Problem Refer

ID: 1054861 • Letter: #

Question

..ooo Sprint 2:37 PM 100% session.masteringchemistry.com C Inquiry Problem Reference the INQUIRY How is the Energy Content of New Fuels Determined? (a pages 344 -345) at the end of Chapter 9 Part A Calculate the PV work in kilojoules done during the combustion of 1 mol of ethanol in which the volume contracts from 77.6 to 49.7 L at a constant external pressure of 1 atm. (Recall that 1 L-atm = 101 J.) Express the energy to three significant figures with the appropriate units. Fuel mass for a given volume A 11.0-gallon fuel tank can hold 32.8 kg of ethanol or 36.6 kg of biodiesel Part B Use the thermochemical equation to calculate the total amount of heat released by burning one tank (11.0 gallons) of ethanol: C2H60(1) + 302(g) 2C02(g) 3H20(1), H, =-1367 kJ Express the heat to three significant figures with the appropriate units. eas Value Units Submit My Answers Give Up Part C Use the thermochemical equations to calculate the total amount of heat released by burning one tank of biodiesel C19H3802 (1) + 27.502(g) 19C02(g) + i9H20(1), H, =-11, 236 kJ Express the heat to three significant figures with the appropriate units. Value Units Submit My Answers Give Up Part D This question will be shown after you complete previous question(s).

Explanation / Answer

A) Work W = P (V2-V1)

= 1 atm x (77.6 L - 49.7 L)

= 27.9 L.atm

= 27.9 x 101 J

= 2817.9 J

B) Molar mass of Ethanol C2H6O = 46 g

46 g of ethanol releases 1367 kJ heat.

i.e. 0.046 kg of ethanol releases 1367 kJ heat.

11 gallons ( 32.8 kg) of ethanol releases ? heat.

? = (32.8 kg/ 0.046 kg) x 1367 kJ

= 974730 kJ heat

Therefore,

  974730 kJ heat will be released.

C)

Molar mass of Biodiesel C19H38O2 = 298 g

298 g of biodiesel releases 11236 kJ heat.

i.e. 0.298 kg of biodiesell releases 11236 kJ heat.

11 gallons ( 36.6 kg) of biodiesel releases ? heat.

? = (36.6 kg/ 0.298 kg) x 11236 kJ

= 1379.9 kJ heat

Therefore,

1379.9 kJ heat will be released.