In recent years, there has been a large push for an increase in the use of renewable resources to produce the energy we need to power our vehicles. One of the newer fuels that has become more widely available is E85, a mixture of 85% ethanol and 15% gasoline. Despite being more environmentally friendly, one of the potential drawbacks of E85 fuel is that it produces less energy than conventional gasoline. Assume a car gets 27.5 mi/gal using gasoline at $3.50/gal and 22.0 mi/gal using E85 at $2.85/gal. A.) How much will it cost to drive 750. miles using conventional gasoline fuel? B.)How much will it cost to drive 750. miles using E85 fuel?

During a recent winter month in Sheboygan, Wisconsin, it was necessary to obtain 3500 kWh of heat provided by a natural gas furnace with 89% efficiency to keep a small house warm (the efficiency of a gas furnace is the percent of the heat produced by combustion that is transferred into the house). (a) Assume that natural gas is pure methane and determine the volume of natural gas in cubic feet that was required to heat the house. The average temperature of the natural gas was 56 F; at this temperature and a pressure of 1 atm, natural gas has a density of 0.68 1 g/L. (b) How many gallons of LPG (liquefied petroleum gas) would be required to replace the natural gas used? Assume the LPG is liquid propane [ C3H8 : density, 0.5318 g/mL; enthalpy of combustion, 2219 Id/mo for the formation of CO2(g) and H2O(l) ] and the furnace used to burn the LPG has the same efficiency as the gas furnace. (c) What mass of carbon dioxide is produced by combustion of the methane used to heat the house? (d) What mass of water is produced by combustion of the methane used to heat the house? (e) What volume of air is required to provide the oxygen for the combustion of the methane used to heat the house? Air contains 23% oxygen by mass. The average density of air during the month was 1.22 g/L. (f) How many kilowatt—hours ( 1kWh=3.6106 J) of electricity would be required to provide the heat necessary to heat the house? Note electricity is 100% efficient in producing heat inside a house. (g) Although electricity is 100% efficient in producing heat inside a house, production and distribution of electricity is not 100% efficient. The efficiency of production and distribution of electricity produced in a coal-fired power plant is about 40%. A certain type of coal provides 2.26 kWh per pound upon combustion. What mass of this coal in kilograms will be required to produce the electrical energy necessary to heat the house if the efficiency of generation and distribution is 40%?

1-86 The specific heats of some elements at 25oC are as follows: aluminum = 0.215 cal/g · oC; carbon (graphite) = 0.170 caI/g oC; iron = 0.107 cal/g mercury = 0.033 1 caI/g oC. (a) Which element would require the smallest amount of heat to raise the temperature of 100 g of the element by 10oC? (b) If the same amount of heat needed to raise the temperature of 1 g of aluminum by 25oC were applied to 1 g of mercury, by how many degrees would its temperature be raised? (c) If a certain amount of heat is used to raise the temperature of 1.6 g of iron by 10oC, the temperature of 1 g of which element would also be raised by 10oC, using the same amount of heat?

This year, like many past years, you begin to feel very sleepy alter eating a large helping of Thanksgiving turkey. Some people attribute this sleepiness to the presence of the amino acid tryptophan in turkey. Tryptophan can be used by the body to produce serotonin, which can calm the brains activity and help to bring on sleep. a. What mass in grams of tryptophan is in a 0.25-lb serving of turkey? (Assume tryptophan accounts for 1.0% of the turkey mass.) b. What mass in grams of tryptophan is in 0.25 quart of milk? (Assume tryptophan accounts for 2.0% of milk by mass and that the density of milk is 1.04 kg/L.)