Alake has a volume of 500,000 m3 with the average surface area being 50,000 m2 and average depth 10m. it is bordered by many wastewater treatment plants which use ozone for wastewater disinfectant before the treated effuluent is released into the lake. there is a single outflow with a flowrate of 1.5m3/sec, which maintains the lake at constant level. bromate is formed as a disinfectant by product of the ozonation process which is put in at a constant average rate of 3,800 kg/yr. the lake is in steady state and can be assumed to be fully mixed.
a. what is the average hydraulic residence time in the lake?
b. what is the concentration of bromate in the lake? assuming the bromate is is a conserved, non-reacting, dissovled constituent.
c. if the input of bromate into the lake could be stopped instantaneously, calculate the time in years required for the average bromate in the lake to decline to 0.02 mg/l. assume the hydraulic throughput continues as before and that the is the only phenomena driving the decline in bromate.

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

When you perform this reaction, what could remain at the end of the reaction? check all that apply. excess reactant aqueous copper chloride excess reactant aluminum oxygen product solid copper carbon dioxide product aqueous aluminum chloride water

For each of the compounds below, show that the charges on the ions add up to zero. a. kbr b. cao c. li(2)o d. cacl(2) e. alcl(3)