Zinc, copper, lead, and mercury ions are toxic to Atlantic salmon at concentrations of 6.42 × 10–2 mM, 7.16 × 10–3 mM, 0.965 mM, and 5.00 × 10–2 mM, respectively. What are the corresponding concentrations in milligrams per liter? Concentration of zinc, copper, lead, and mercury? _____ Mg/mL.
1 ppm = 1 mg/L
For Zn, toxic level is 6.42E-2 mM.
That is 6.42E-5 M = 6.42E-5 mols/L. So in 1 L solution we have 6.42E-5 mols and grams Zn = mols Zn x atomic mass Zn and that gives you grams Zn/L. Convert to mg Zn/L and that is that many ppm.
grams Zn = m
To find the corresponding concentrations of zinc, copper, lead, and mercury in milligrams per liter (mg/L), we need to convert the given concentrations from millimoles per liter (mM) to milligrams per liter (mg/L).
To convert from millimoles per liter (mM) to milligrams per liter (mg/L), you need to use the molar mass of each ion.
The molar mass of zinc (Zn) is approximately 65.38 g/mol, copper (Cu) is approximately 63.55 g/mol, lead (Pb) is approximately 207.2 g/mol, and mercury (Hg) is approximately 200.59 g/mol.
Now we can use the following formula:
Concentration in mg/L = (Concentration in mM) * (Molar mass in mg/mol)
Let's calculate the concentrations for each ion:
1. Zinc (Zn):
Concentration in mg/L = (6.42 × 10^-2 mM) * (65.38 mg/mol) = 4.20 mg/L
2. Copper (Cu):
Concentration in mg/L = (7.16 × 10^-3 mM) * (63.55 mg/mol) = 0.46 mg/L
3. Lead (Pb):
Concentration in mg/L = (0.965 mM) * (207.2 mg/mol) = 200.32 mg/L
4. Mercury (Hg):
Concentration in mg/L = (5.00 × 10^-2 mM) * (200.59 mg/mol) = 10.03 mg/L
Therefore, the corresponding concentrations of zinc, copper, lead, and mercury in mg/L are approximately:
Zinc: 4.20 mg/L
Copper: 0.46 mg/L
Lead: 200.32 mg/L
Mercury: 10.03 mg/L
So, the answer is:
Zinc concentration: 4.20 mg/L
Copper concentration: 0.46 mg/L
Lead concentration: 200.32 mg/L
Mercury concentration: 10.03 mg/L