How can the gas produced in a chemical reaction be studied?

Using the right-pointing arrow above implies that all reactants turn into products. For example, we can make water by reacting hydrogen with oxygen. The reactants are hydrogen and oxygen. The product is water in the gas phase because the reaction produces a lot of heat.

Molarity is moles of solute over liters of solution. idk if that is what you are talking about, but you can convert moles of solute to grams of solute using dimensional analyzes by using molar mass found on the periodic table.