Calculate the grams of solute in each of the following solutions: (a) \(1.20 \mathrm{~L}\) of \(18 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}\) (b) \(27.5 \mathrm{~mL}\) of \(1.50 \mathrm{M} \mathrm{} \mathrm{KMnO}_{4}\) (c) \(120 \mathrm{~mL}\) of \(0.025 \mathrm{M} \mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}\)

Molar mass is a fundamental concept in chemistry that refers to the mass of one mole of a substance, usually expressed in grams per mole (g/mol). It is calculated by adding the atomic masses of all the atoms in a molecule. For example, water (H₂O) has a molar mass of approximately 18 g/mol because it consists of two hydrogen atoms (each with an atomic mass of approximately 1 g/mol) and one oxygen atom (approximately 16 g/mol).

Understanding molar mass is crucial for converting between the mass of a substance and the amount of substance in moles. It's the bridge between the microscopic world of atoms and molecules and the macroscopic world we measure in labs.

Molarity to grams conversion is a technique used to find the mass of a solute in a given volume of solution. Molarity, defined as the number of moles of solute per liter of solution (mol/L), tells us the concentration of a substance in a solution. To perform this conversion, you first need to find the number of moles of solute using the equation: \
\( \text{Moles} = \text{Molarity} \times \text{Volume} \)

Once the number of moles is found, you can convert it to grams by multiplying it by the substance's molar mass. This process is illustrated in the textbook exercise, where the molarity and volumes of different solutions were given, and the task was to find the mass of the dissolved substances. By mastering this conversion, students learn to transition seamlessly from conceptual to practical applications of molarity in the laboratory.

Stoichiometry is a section of chemistry that involves calculating the relative quantities of reactants and products in chemical reactions. It is based on the conservation of mass and the concept of the mole. In molarity calculations, stoichiometry comes into play when you need to know how different substances in a reaction relate to one another quantitatively.

For instance, if a chemical equation indicates that two moles of hydrogen react with one mole of oxygen to form water, stoichiometry allows us to calculate the amount of oxygen needed to react with a certain volume of hydrogen at a known molarity or the volume of water produced from this reaction. Learning stoichiometry provides students with the skills to predict the outcomes of chemical reactions, which is essential for both academic and real-world lab settings.