Question

In the summer, the dissolved oxygen level is 40. What is the carbon fix (mg C/L) during summer, and how did you get to that answer?

A) 20 mg C/L
B) 30 mg C/L
C) 40 mg C/L
D) 50 mg C/L

Answer 1

The dissolved oxygen concentration in water can be estimated using Henry's law. We can calculate the dissolved oxygen concentration at 15 °C by interpolating the Henry's law constant. The concentration can then be converted from mol/L to mg/L.

Step-by-step explanation:

The dissolved oxygen concentration in water is influenced by factors such as temperature, pressure, and the presence of other gases. At 15 °C, we can estimate the dissolved oxygen concentration using Henry's law. The Henry's law constant for O₂ is 1.3 × 10-³ M/atm at 25 °C, and assuming ideal solution behavior, we can calculate the concentration of dissolved oxygen at 15 °C by linearly interpolating.

Interpolating between 25 °C and 15 °C, we can estimate the Henry's law constant at 15 °C. Using this constant, we can determine the dissolved oxygen concentration when the partial pressure of O₂ is at the approximate atmospheric pressure of 155 torr (20.7 kPa).

Finally, to convert the concentration from mol/L to mg/L, we can use the conversion factor (2.0 x 10-4 mol/L) (32.0 g/1 mol) (1000 mg/g).