Propranolol 1C16H21NO22, a so-called beta-blocker that is used for treatment of high blood pressure, is effective at a blood plasma concentration of 50 ng/L. Express this concen- tration of propranolol in the following units: (b) Molarity

Verified step by step guidance

1. Identify the molecular formula of propranolol: \( C_{16}H_{21}NO_2 \).
2. Calculate the molar mass of propranolol by adding the atomic masses of all atoms in the formula: \( 16 \times \text{C} + 21 \times \text{H} + 1 \times \text{N} + 2 \times \text{O} \).
3. Convert the concentration from ng/L to g/L by dividing by \( 10^9 \).
4. Use the formula for molarity: \( M = \frac{\text{moles of solute}}{\text{liters of solution}} \).
5. Calculate the moles of propranolol using the formula: \( \text{moles} = \frac{\text{mass in grams}}{\text{molar mass}} \), and then divide by the volume in liters to find molarity.

Key Concepts

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 (like ng/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

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 atoms in a molecule. For propranolol (C16H21NO2), the molar mass is essential for converting its concentration from mass (ng/L) to moles (M), enabling the calculation of molarity.

Unit Conversion

Unit conversion is the process of converting a quantity expressed in one set of units to another set of units. In this context, converting from ng/L to molarity involves converting nanograms to grams and liters to milliliters, while also applying the molar mass of propranolol. Mastery of unit conversion is crucial for accurately expressing concentrations in different units.