The following replicate values were reported for the concentration of magnesium chloride, MgCl2, in mol/L. What value should be reported as the mean concentration of the chloride ion, Cl, converted to ppm? (You may use the simplified definition of ppm.)0.00141, 0.00138, 0.00175, 0.00134, 0.00132F MgCl2
To find the mean concentration of the chloride ion, Cl⁻, converted to parts per million (ppm), we first need to determine the concentration of Cl⁻ in each magnesium chloride solution.
The formula for magnesium chloride, MgCl₂, tells us that there are two chloride ions for every one magnesium ion. This means that to calculate the concentration of Cl⁻, we can divide the concentration of MgCl₂ by 2.
Next, we need to convert the concentration of Cl⁻ into parts per million (ppm). The simplified definition of ppm states that 1 ppm is equal to 1 mg/L (or 1 mg/kg).
Here's how we can calculate the mean concentration of Cl⁻ in ppm step by step:
1. Find the concentration of Cl⁻ in each solution:
- For the first solution: Cl⁻ concentration = 0.00141 mol/L ÷ 2 = 0.000705 mol/L
- For the second solution: Cl⁻ concentration = 0.00138 mol/L ÷ 2 = 0.00069 mol/L
- For the third solution: Cl⁻ concentration = 0.00175 mol/L ÷ 2 = 0.000875 mol/L
- For the fourth solution: Cl⁻ concentration = 0.00134 mol/L ÷ 2 = 0.00067 mol/L
- For the fifth solution: Cl⁻ concentration = 0.00132 mol/L ÷ 2 = 0.00066 mol/L
2. Convert the concentration of Cl⁻ into ppm:
- For the first solution: Cl⁻ concentration in ppm = 0.000705 mol/L × 1000 mg/L = 0.705 mg/L (or ppm)
- For the second solution: Cl⁻ concentration in ppm = 0.00069 mol/L × 1000 mg/L = 0.69 mg/L (or ppm)
- For the third solution: Cl⁻ concentration in ppm = 0.000875 mol/L × 1000 mg/L = 0.875 mg/L (or ppm)
- For the fourth solution: Cl⁻ concentration in ppm = 0.00067 mol/L × 1000 mg/L = 0.67 mg/L (or ppm)
- For the fifth solution: Cl⁻ concentration in ppm = 0.00066 mol/L × 1000 mg/L = 0.66 mg/L (or ppm)
3. Calculate the mean concentration of Cl⁻ in ppm:
- Mean Cl⁻ concentration in ppm = (0.705 + 0.69 + 0.875 + 0.67 + 0.66) / 5 = 0.720 mg/L (or ppm)
Therefore, the mean concentration of the chloride ion, Cl⁻, converted to ppm, is 0.720 mg/L (or ppm).