Fuel - severe and prolonged shortage of petroleum

In the event of a severe and prolonged shortage of petroleum, suggest one alternative fuel that could be used for automobiles. What do you see as the advantages and disadvantages of your choice of alternative fuel?

Rate of destruction of methane

At an altitude of 35 kilometers, the average concentrations of O* and of CH4 are approximately 100 and 1E11 molecules cm-3 respectively, and the rate constant k for the above reaction is approximately 4.0E-10 cm3 Molecules-1 s-1. Calculate the rate of destruction of methane in molecules per second per cubic centimeter.

How much Fe++ could be present in water containing 2 x 1e-02 M HCO3- (bicarbonate) without causing the precipitation of FeCO3 (Ksp=10**(-10.7))

How much Fe++ could be present in water containing 2 x 1e-02 M HCO3- (bicarbonate) without causing the precipitation of FeCO3 (Ksp=10**(-10.7))

Amount of calcium carbonate dissolved

The average pH of precipitation in rural areas is 6.80. Assuming that the pH is controlled by the carbonate system, i.e., no anthropogenic acid gases are present in the atmosphere, calculate the amount of calcium carbonate (mg) dissolved per liter of rainwater. pKa1=6.33, KCO2=3.388e-02 I've seen a couple different solutions to this problems and all of them use other constants and numbers that I have no idea where they got them from. Please explain

Concentration of nitric oxide

At combustion temperatures, the equilibrium constant for the reaction N2 + O2 -> 2NO is about 4.0E-14. Calculate the concentration(atm) of nitric oxide that is in equilibrium with atmospheric levels of nitrogen and oxygen.