Determining the Number of Moles in 75 Grams of H2SO4: An In-Depth Guide

Understanding the concept of molar mass and how to calculate the number of moles in a given substance is fundamental in the field of chemistry. This article provides a detailed explanation on determining the number of moles in 75 grams of H2SO4, a commonly encountered inorganic compound. We will also clarify the difference between atomic mass and molar mass and demonstrate step-by-step how to calculate the molar mass of H2SO4.

Introduction to Molar Mass and Moles

The molar mass of a substance is defined as the sum of the atomic masses of all the atoms that make up the molecule of the substance. This concept is crucial in converting the mass of a substance to the number of moles. The number of moles, on the other hand, represents the amount of substance that contains as many particles (atoms, molecules, or ions) as there are atoms in 12 grams of carbon-12.

Understanding H2SO4

H2SO4, known commonly as sulfuric acid, is a strong diprotic acid that undergoes ionization in water. The ionization process of H2SO4 in water is noteworthy as it does not form molecules but instead ionizes into hydronium ions (H3O ) and sulfate ions (SO4^2-).

Calculating the Molar Mass of H2SO4

To determine the molar mass of H2SO4, we need to add up the molar masses of all the atoms in its formula. The molar mass of each element can be found on the periodic table. For H2SO4, we have:

H2: 1.01 g/mol x 2 2.02 g/mol S: 32.07 g/mol O4: 16.00 g/mol x 4 64.00 g/mol

Total molar mass of H2SO4: 2.02 32.07 64.00 98.09 g/mol

Calculating the Number of Moles in 75 Grams of H2SO4

The number of moles in a substance can be calculated using the formula:

[n frac{mass}{molar , mass}]

In our case, we are given 75 grams of H2SO4, and the molar mass of H2SO4 is 98.09 g/mol. Thus, the calculation becomes:

[n frac{75 , text{g}}{98.09 , text{g/mol}} approx 0.765 , text{mol}]

Additional Insights and Applications

Understanding the number of moles in a substance helps in many applications, from laboratory experiments to industrial processes. For instance, in chemical reactions, the number of moles of reactants and products is crucial for stoichiometric calculations. Additionally, knowing the molar mass and the number of moles can help in determining the concentration of solutions and the yield of chemical reactions.

It is also worth noting that the ionization process of H2SO4 in water can be represented as:

[H2SO4 rightarrow 2H^ SO4^{2-}]

This ionization is important in understanding the pH of solutions containing H2SO4.

Conclusion

Determining the number of moles in a substance requires a clear understanding of molar mass and the proper application of the formula (n frac{mass}{molar , mass}). This guide has provided a step-by-step approach to calculating the molar mass and the number of moles in 75 grams of H2SO4. By mastering these concepts, you can apply them to a wide range of chemical problems and calculations.

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