Formula used for determining the molarity is:
-(1)
Number of moles of solute that is is determined as:
-(2)
Mass of the solute can be calculated as:
- (3)
density of rain water = 1.00 g/mL (given)
Concentration of = 0.2 ppb (given)
Since,
So, 0.2 ppb =
Substituting the values in formula (3):
Mass = (As 1 mg = g).
Now, substituting the values of mass and formula mass in formula (2):
Number of moles =
Volume of solution = 1 L
Substituting the values of number of moles and volume of solution in formula (1):
Molarity =