Final answer:
The concentration of nitrate in the water sample is 10 ppm, which is equivalent to 0.0001613 mol/L, 2.26 mg N/L, and 10,000 ppb.
Step-by-step explanation:
The concentration of nitrate (NO3−) in a water sample is given as 10 mg NO3−/L. We can express this concentration in various units such as parts per million (ppm), moles per liter (mol/L), and parts per billion (ppb).
(a) Concentration in ppm
There doesn't seem to be a standard unit called 'ppmm,' so this part may be a typo or misunderstanding. Usually, we refer to ppm (parts per million) which, in aqueous solutions, is equal to mg/L. Therefore, the concentration is 10 ppm since 1 ppm = 1 mg/L.
(b) Concentration in moles/L
To convert to moles per liter, we need to know the molar mass of NO3−, which is approximately 62 g/mol. Thus, the conversion is:
- 10 mg NO3− / L × (1 g / 1000 mg) × (1 mol / 62 g) = 0.0001613 mol/L
(c) Concentration in mg NO3−-N/L
The nitrogen atom in a nitrate ion (NO3−) contributes to part of the total mass. The molar mass of nitrogen (N) is approximately 14 g/mol. Therefore, the conversion of mg NO3−/L to mg NO3−-N/L is:
- 10 mg NO3− / L × (14 g/mol N / 62 g/mol NO3−) = 2.26 mg N/L
(d) Concentration in ppb
Converting ppm to ppb (parts per billion), we know that 1 ppm is 1,000 times less than 1 ppb. Therefore:
- 10 ppm × 1000 = 10,000 ppb