Question

In: Chemistry

The following measurements were made at a large lake: pH 8.5 Alkalinity = 3.4 meq/L [Ca2+]...

The following measurements were made at a large lake:

pH 8.5

Alkalinity = 3.4 meq/L

[Ca2+] = 32 mg/L

[SO4 2– ] = 22 mg/L

[Mg2+] = 32 mg/L

[Cl– ] = 27 mg/L

[Na+ ] = 1 mg/L

total dissolved solids = 260 mg/L

[K+ ] = 3.2 mg/L

(a) Using the alkalinity equation and the measured alkalinity, estimate the total carbonate concentration ([Carb]tot or CT) of the water (note that pH is given).

(b) Calculate the charge balance for this water (remember to convert charge to eq L-1 ). Include HCO3 – , and CO3 2– in your charge balance by calculating their concentrations using the total carbonate concentration determined in (a). How good is the charge balance using these measurements? Doing your calculations in an Excel spreadsheet (or PhreeqC) will save time.

(c) For the total dissolved solids measured for this solution, estimate the expected conductivity? Hint: Based on this analysis, does this water approximate a NaCl solution or a CaCO3 solution?

Expert Solution

queen_honey_blossom answered 2 years ago

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