How many grams of solute would you use to prepare each of the following solutions? (b) 167 mL of 0.200 M boric acid (H₃BO₃)

Verified step by step guidance

1. Determine the molar mass of boric acid (H_3BO_3) by adding the atomic masses of its constituent elements: 3 hydrogen atoms, 1 boron atom, and 3 oxygen atoms.
2. Use the formula for molarity (M) which is M = \frac{moles\ of\ solute}{liters\ of\ solution} to find the moles of boric acid needed. Here, M = 0.200 M and the volume of the solution is 167 mL, which needs to be converted to liters.
3. Convert the volume from milliliters to liters by dividing by 1000.
4. Calculate the moles of boric acid required using the molarity equation: moles = Molarity \times Volume\ in\ liters.
5. Convert the moles of boric acid to grams using the molar mass calculated in the first step: grams = moles \times molar\ mass.

Key Concepts

Molarity (M)

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is expressed in moles per liter (mol/L). To calculate the amount of solute needed for a solution, one must know the desired molarity and the volume of the solution in liters.

Moles of Solute

A mole is a unit in chemistry that represents 6.022 x 10²³ entities, such as atoms or molecules. To find the number of moles of solute required for a solution, you can multiply the molarity of the solution by the volume in liters. This calculation is essential for determining how much solute to weigh out.

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. Knowing the molar mass of the solute allows you to convert moles of solute into grams, which is necessary for preparing the solution.