Simple 2-part question - heating water
14a) Should you install a solar water heater? The average home has a 200 liter hot-water tank, which is effectively drained and replenished three times per day. Assume that the entering tap water is 19 degrees Centigrade and is heated to 53 degrees Centigrade. Given an average energy from sunlight of 1.53 kJ/cm2 per day, how lar ...continues
Rate of destruction of methane
At an altitude of about 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 3.4E-10 cm3 Molecules-1 s-1. Calculate the rate of destruction of methane in molecules per second per cubic centimeter.
29) A groundwater sample , at 25 degrees C, has Eh= 1.00 and the pH=6.800. When the system is at equilibrium, calculate the amount ofdissolved oxygen (in ppm) in the ground water sample.
#29b) At a pH of 6.0 and pE 3.0, what's the concentrationn of Fe2+ (in mol/L) in equillibrium with Fe(OH)3? Hint from instructor in email: Use the Nernst equation and the Ksp for the solubility of solid iron (III) hydroxide.
21) Assume a wind turbine w/ a hub 50m above ground, a rotor diameter of 25m, and a wind conversion efficientcy of 25 percent. The turbine operates in an area w/ an average windpower density of 600 watts/sq meter at 50m altitude. How much electricity (in kwH) can the turbine generate per year?Wind densities greater than or equal ...continues
Dissolved oxygen question w/hint
A ground water sample , at 25 degrees C, has Eh= 1.0 and pH=6.80. Assuming the system is at equilibrium, calculate the amount of dissolved oxygen (ppm) in the groundwater sample Hint: [O2-aq]/[O2-g]=0.0012589
General Chemistry / Environmental chem question
44) How many metric tonnes of 5%-S coal would be required to yield the H2SO4 needed to produce a 2.0-cm rainfall of pH 2.00 over an area of 100 square kilometers? HINT: Hint: Calculate vol rain, mol H+, mass of S, mass of coal
71) What is the redox potential of an acid mine water sample which has Fe3+ = 7 x E-03 M and Fe2+ = 4 x E-04 M given that E0 for the Fe3+/Fe2+ couple is 0.77v. Hint: Use Nernst equation
How many metric tons of 5%-S coal would be needed to yield the H2SO4 required to produce a 2.0-cm rainfall of pH 2.00 over an area of 100 square kilometers? Hint: Calculate vol rain, mol H+, mass of S, mass of coal
Photosynthesis related question
a) Photosynthesis is estimated to produce 340.0 g (dry weight) of plant matter per square meter, 50% of which is carbon. Calculate the total number of grams of carbon "fixed" each year by 1000 square meters. b) The photosynthetic reaction can be represented as: 6CO2 + 6H2O -> C6H12O6 + 6O2 Of the glucose produced, 40.0% is ...continues
