Residues of the herbicide atrazine (C₈H₁₄ClN₅) in water can be detected at concentrations as low as 0.050 µg/L. Express this concentration of atrazine in the following units: (a) Parts per billion (assume a solution density of 1.00 g/mL)

Verified step by step guidance

1. Understand that parts per billion (ppb) is a way to express very dilute concentrations of substances. It is defined as the mass of the solute divided by the mass of the solution, multiplied by 10^9.
2. Since the density of the solution is given as 1.00 g/mL, we can assume that 1 L of the solution has a mass of 1000 g (since 1 L = 1000 mL).
3. Convert the concentration from micrograms per liter (µg/L) to grams per liter (g/L) by recognizing that 1 µg = 10^-6 g. Therefore, 0.050 µg/L is equivalent to 0.050 x 10^-6 g/L.
4. Calculate the mass of atrazine in grams in 1 L of solution, which is 0.050 x 10^-6 g.
5. To find the concentration in ppb, divide the mass of atrazine in grams by the mass of the solution in grams (1000 g), and then multiply by 10^9 to convert to ppb.