Final answer:
To calculate the minimum mass of H2SO4 needed, you must use the balanced chemical equation and stoichiometry to convert from moles of the substance you're reacting it with to moles of H2SO4, and then to grams.
Step-by-step explanation:
To find the minimum mass of H2SO4 you'd need for a reaction, you must first know the balanced chemical equation and the amount of the substance you are reacting it with. In some cases, the problem might give you a specific reaction to react H2SO4 with, such as barium chloride (BaCl2). For instance, the equation for the reaction between H2SO4 and BaCl2 is:
BaCl2 + H2SO4 → BaSO4 + 2HCl
From the balanced equation, you can see that the mole ratio of BaCl2 to H2SO4 is 1:1. If you have 2 g of BaCl2, you first determine the moles of BaCl2 by using its molar mass and then use the mole ratio to find the moles of H2SO4 needed. After finding the moles of H2SO4, you would then convert those moles to grams utilizing the molar mass of H2SO4, which is 98.079 g/mol, to determine the minimum mass required.