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: (b) Molarity

Molarity (M) is a measure of concentration defined as the number of moles of solute per liter of solution. It is commonly used in chemistry to express the concentration of a substance in a solution. To convert from mass concentration (mg/L) to molarity, one must know the molar mass of the solute, which allows for the calculation of moles from the given mass.

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all the atoms in a molecule. For atrazine (C8H14ClN5), the molar mass is essential for converting the concentration from mg/L to moles per liter, which is necessary for expressing the concentration in molarity.

Unit conversion is the process of converting a quantity expressed in one set of units to another set of units. In this context, it involves converting the concentration of atrazine from milligrams per liter (mg/L) to molarity (M). This requires using the molar mass of atrazine to relate the mass of the solute to the number of moles, facilitating the conversion to the desired concentration unit.