1. What are the basic parts of a battery? How do batteries generate electrical current?

2. If someone suggests placing a battery in the refrigerator to prolong its life, will you agree or not? Justify your answer.

3. Two of the emerging technologies in reducing automobile emissions are electric cars
and hydrogen fuel cars. Both work by converting chemical energy to electrical energy
then to mechanical energy. However, electric cars require charging stations, while
hydrogen fuel cars require refilling stations. Which technology is better? Why?

a) A 12 V lead-acid car battery, engineered for 'up to 500 or more charge/discharge cycles', has a rating of 135.0 A hr. (It sells for $144.00.) Calculate the total amount of charge that moves through the battery before it needs to be recharged.
4.86×10⁵ C

b) What is the total electrical energy that the battery can deliver before it needs to be recharged?
5.83×10⁶ J

c) The total mass of the battery is 18.1 kg. (It weighs 40 lb). What fraction of that mass is converted to electrical energy by the battery before it needs to be recharged?

d) How many kilograms of such batteries would be required to get the same mechanical energy (essentially mileage, for cars of the same total weight) as 16 gallons of gasoline? Assume that the efficiency of an electrically powered car is 2.5 times that of a gasoline-powered car for the conversion to mechanical energy. DATA: Energy content of 1 gallon of gas = 1.32 x 10⁸ J.

e) One gallon of gasoline (mass = 2.8 kg) requires about 8.9 kg of Oxygen for combustion. What fraction of the mass is converted to energy?

In what type of molecular energy is temperature mostly related to?

A. Potential Energy

B. Kinetic Energy

C. Electrical Energy

D. Mechanical Energy in general

Hydrogen gas has the potential for use as a clean fuel in reaction with oxygen. The relevant reaction is

2 H₂(g) + O₂(g) 2 H₂O(l)

Consider two possible ways of utilizing this reaction as an electrical energy source: (i) Hydrogen and oxygen gases are combusted and used to drive a generator, much as coal is currently used in the electric power industry; (ii) hydrogen and oxygen gases are used to generate electricity directly by using fuel cells that operate at 85 °C. (a) Use data in Appendix C to calculate ∆H° and ∆S° for the reaction. We will assume that these values do not change appreciably with temperature. (b) Based on the values from part (a), what trend would you expect for the magnitude of ∆G for the reaction as the temperature increases? (c)What is the significance of the change in the magnitude of ∆G with temperature with respect to the utility of hydrogen as a fuel? (d) Based on the analysis here, would it be more efficient to use the combustion method or the fuel-cell method to generate electrical energy from hydrogen?