Explanation:
To solve this problem, we need to calculate the final concentrations of CuSO4 in each tube after the serial dilution.
Given information:
- Stock solution: 36 μL of 800 ppm CuSO4
- Diluent volume: 324 μL of wash buffer
- Total volume in T1: 360 μL
- Dilution factor: 240
Step 1: Calculate the mass of CuSO4 in the stock solution.
Mass of CuSO4 in stock solution = (36 μL × 800 ppm) / 1,000,000 = 0.0288 mg
Step 2: Calculate the concentration of CuSO4 in T1.
Concentration of CuSO4 in T1 = (0.0288 mg) / (360 μL) = 0.08 mg/mL = 80 ppm
Step 3: Calculate the concentrations of CuSO4 in the remaining tubes.
T2: Dilution factor = 240, so the concentration is 80 ppm / 240 = 0.333 ppm
T3: Dilution factor = 240, so the concentration is 0.333 ppm / 240 = 0.00139 ppm
T4: Dilution factor = 240, so the concentration is 0.00139 ppm / 240 = 0.0000058 ppm
T5: Dilution factor = 240, so the concentration is 0.0000058 ppm / 240 = 0.0000000242 ppm
Therefore, the answers are:
a) 80 ppm
b) 0.333 ppm
c) 0.00139 ppm
d) 0.0000058 ppm
e) 0.0000000242 ppm
