1.) Two determinations of the dissolved oxygen content of a 200 mL sample of water, made five days apart, gave 5.3 ppm and 2.2 ppm of dissolved O2 respectively. What is the biological oxygen demand of the sample? The following formula was given to us:
BOD= mg dissolved 02 consumed/ Liter of water
but I'm not sure how to convert ppm to mg dissolved 02 consumed
2.) A 25.00 mL sample of a standard solution containing 1.0 g of CaCO3/L required 20.20 mL of EDTA to fully complex the Ca present. Calculate the volume of EDTA stoichiometrically equivalent to 1.0 mg of CaCo3© BrainMass Inc. brainmass.com October 10, 2019, 12:39 am ad1c9bdddf
This solution helps go through chemistry concepts such as biological oxygen demand and water hardness.