The dissolved Ca++ concentration in a river is approximately 30 mg/L.

This concentration is equivalent to ___ ppm
or ___ mol/L,
or ___ cmol/L.
It would provide ___ cmolc+/L.
(c+ is a subscript)

30 mg/L is the same as 30 ppm.

how do you convert mg to moles?

mols = grams/molar mass

To find the equivalent concentration in various units, we can first convert the given concentration of Ca++ from mg/L to the desired units.

1. To convert from mg/L to ppm:
Since 1 mg/L is equivalent to 1 ppm, the dissolved Ca++ concentration of 30 mg/L is also equivalent to 30 ppm.

2. To convert from mg/L to mol/L:
First, we need to calculate the molar mass of calcium (Ca). Calcium has an atomic mass of 40.08 g/mol.
To convert from mg to g, we divide by 1000 (since there are 1000 mg in 1 g).
Next, we convert from g to mol by dividing by the molar mass.
Therefore, the dissolved Ca++ concentration of 30 mg/L is equivalent to (30/1000)/40.08 = 0.000748 mol/L (rounded to the appropriate number of significant figures).

3. To convert from mol/L to cmol/L:
Since 1 mol/L is equivalent to 10 cmol/L, the dissolved Ca++ concentration of 0.000748 mol/L is also equivalent to 0.00748 cmol/L (rounded to the appropriate number of significant figures).

4. To find the cmolc+/L value:
The dissolved Ca++ concentration represents the concentration of Ca++ ions, which have a charge of 2+. Therefore, to find the cmolc+/L value, we can divide the cmol/L value by 2.
Thus, the dissolved Ca++ concentration of 0.00748 cmol/L would provide 0.00748/2 = 0.00374 cmolc+/L (rounded to the appropriate number of significant figures).

Therefore, the dissolved Ca++ concentration of 30 mg/L is equivalent to 30 ppm, 0.000748 mol/L, 0.00748 cmol/L, and 0.00374 cmolc+/L.