1. Consider the conductance meter and the titration method of determining the salt content of a brine sample. Discuss at least two advantages and two disadvantages of each method.
2. A corrosion technologist pipetted a 50.00 mL sample of an unknown brine and titrated it with 37.64 mL of 0.1024 M silver nitrate solution. Calculate the ppm salt (NaCl) in the sample.
3. If a salty crude sample was analyzed to have 110.6 ppm salts, calculate the pounds of salt per 1000 bbls of crude
I'll leave #1 for you. After you've done the titrations you can better discuss the adv and disadv.
#2. moles AgNO3 used = M x L = 0.03764 x 0.1024 = 0.003854 moles.
moles NaCl = 0.003854
grams NaCl = moles x molar mass = 0.003854 x 58.44 = 0.22525 grams NaCl in a 50 mL sample which is
0.22525/50 = 0.00450 g NaCl/mL.
Change that to mg/L and that will be ppm.
1. Conductance Meter Method:
Advantages:
- Quick and easy: Conductance measurements can be made rapidly, allowing for high sample throughput.
- Non-destructive: The conductance meter method does not require additional reagents to be added to the sample, meaning the sample is not altered or consumed during the analysis.
Disadvantages:
- Sensitivity to impurities: Conductance measurements can be affected by impurities or other ions present in the solution, leading to potential inaccuracies.
- Calibration requirements: Conductance meters need to be regularly calibrated using standard solutions to ensure accurate readings, which can be time-consuming.
Titration Method:
Advantages:
- Accurate and precise: Titration is a widely accepted method for determining the salt content of a solution and can provide highly accurate results.
- Flexibility: Titration methods can be adapted to different salt analytes by selecting appropriate titrants, making it a versatile technique.
Disadvantages:
- Time-consuming: Titration can be a slow process, especially if the analyte requires a high concentration of titrant for complete reaction.
- Required reagents: The titration method requires specific reagents to be added to the sample, which can introduce errors if not added precisely or if the reagents are impure.
2. To calculate the ppm salt (NaCl) in the sample using the titration results, you'll need to use the equation:
ppm salt = (volume of titrant * molarity of titrant * molar mass of NaCl) / volume of sample
Given:
Volume of titrant (Vtitrant) = 37.64 mL
Molarity of titrant (Mtitrant) = 0.1024 M
Molar mass of NaCl = 58.44 g/mol
Volume of sample (Vsample) = 50.00 mL (convert to L by dividing by 1000, i.e., 0.0500 L)
Substituting the given values into the equation:
ppm salt = (37.64 mL * 0.1024 M * 58.44 g/mol) / 0.0500 L
Calculating this expression will give you the ppm salt (NaCl) in the sample.
3. To calculate the pounds of salt per 1000 bbls of crude using the given ppm salt value, you can follow these steps:
Step 1: Convert ppm to mass percent:
Mass percent = ppm salt * 0.0001
Step 2: Convert mass percent to pounds per barrel:
Pounds per barrel = Mass percent * 10 * 42
Given:
ppm salt = 110.6 ppm
Substituting the given value into Step 1:
Mass percent = 110.6 ppm * 0.0001 = 0.01106%
Substituting the mass percent into Step 2:
Pounds per barrel = 0.01106% * 10 * 42
Calculating this expression will give you the pounds of salt per 1000 barrels of crude.