How to Calculate the Moles of Oxygen in H3PO4: A Detailed Guide

Understanding how to calculate the moles of a particular element, like oxygen (O), in a compound such as H3PO4 (phosphoric acid), is a crucial skill for students, researchers, and professionals in chemistry and related fields. This guide will walk you through the steps, explaining the concepts and providing a detailed example.

Understanding Molar Mass and Stoichiometry

Molar mass is the mass of one mole of a substance. It is expressed in grams per mole (g/mol). For H3PO4, we first need to determine its molar mass. The molar mass of H3PO4 is:

Hydrogen (H): 1.01 g/mol (3 atoms) 3.03 g/mol Phosphorus (P): 30.97 g/mol (1 atom) 30.97 g/mol Oxygen (O): 16.00 g/mol (4 atoms) 64.00 g/mol Total molar mass of H3PO4: 3.03 g/mol 30.97 g/mol 64.00 g/mol 98.00 g/mol

Stoichiometry involves the study of the quantitative relationships between reactants and products. In the context of calculating the moles of a specific element in a compound, we use the molar mass to determine the number of moles.

Step-by-Step Calculation of Moles of Oxygen in H3PO4

The problem states that 98 g of H3PO4 contains 4 moles of oxygen atoms. We will use this information to find out how many moles of oxygen are in 4.9 g of H3PO4.

Determine the molar mass of H3PO4: We have already calculated that 98 g of H3PO4 contains 4 moles of oxygen atoms. This confirms that the molar mass of H3PO4 is 98 g/mol. Set up the proportion: We know that 98 g of H3PO4 contains 4 moles of oxygen atoms. Therefore, to find the number of moles of oxygen in 4.9 g of H3PO4, we can set up the following proportion: 98 g of H3PO4 contains 4 moles of O 4.9 g of H3PO4 contains x moles of O Solve for x: x (4 moles of O) × (4.9 g of H3PO4) / (98 g of H3PO4) x 4 × 4.9 / 98 x 19.6 / 98 x 0.2 moles of O

Conclusion and Further Exploration

In conclusion, 4.9 g of H3PO4 contains 0.2 moles of oxygen atoms. This calculation is a fundamental skill in chemistry, and understanding it can help you tackle more complex problems. For further exploration, you may want to try calculating the moles of other elements in H3PO4 or other compounds.

Related Keywords

moz calculation H3PO4 oxygen atoms