What is the approximate molar concentration of Na⁺ ions in a solution prepared by dissolving 8.2 g of Na₃PO₄ (MM = 163.94 g/mol) into 250 mL of water?

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11ecba2d_124e_9fdb_a3bf_89bbca3c67b3_MD0008_00 The molar concentration (molarity) of a chemical species is defined as the number of moles of the species per liter of solution (mol/L). If a concentration is known in terms of the mass of solute per unit volume, the mass must be converted into moles and the volume expressed in liters to correctly determine the molarity. The mass of a compound sample can be converted into the equivalent number of moles using the molar mass, which is the amount of mass contained in 1 mole of the compound (grams per mole). In this question, dividing the 8.2 g of Na₃PO₄ in the solution by the molar mass of Na₃PO₄ gives: 11ecba2d_124e_c6ec_a3bf_3f86344ce777_MD0008_00 The moles of one chemical species can be related to the moles of another chemical species by the mole ratios (stoichiometry) from a chemical reaction or compound formula. The formula of Na₃PO₄ shows that 3 moles of Na⁺ ions are released into solution for every 1 mole of Na₃PO₄ that dissolves: 11ecba2d_124e_c6ed_a3bf_77493de3e621_MD0008_00 Applying this 3:1 ratio gives the Na⁺ ions released into solution: 11ecba2d_124e_c6ee_a3bf_93e23f4922a1_MD0008_00 Dividing the moles of Na⁺ ions in solution by the total volume of solution expressed in liters (0.25 L) yields: 11ecba2d_124e_c6ef_a3bf_fdb7dcbeba2a_MD0008_00 Therefore, the molar concentration of Na⁺ ions is 6.0 × 10⁻¹ M. (Choice A) A concentration of 6.0 × 10⁻⁴ mol/mL is calculated if the solution volume is not converted to liters. Molarity is defined as moles per liter rather than moles per milliliter. (Choice B) Expressing the concentration in terms of mass per unit volume gives 3.3 × 10⁻² g/mL of Na₃PO₄ instead of the molar concentration (mol/L) of Na⁺ ions. (Choice C) A concentration of 2.0 × 10⁻¹ M is the molarity of the Na₃PO₄ rather than the molarity of the Na⁺ ions. The 3:1 mole ratio of Na⁺ to Na₃PO₄ makes the Na⁺ concentration three times higher than that of Na₃PO₄. Educational objective: The molar concentration (molarity) of a chemical species is defined as the number of moles of the species per liter of solution (mol/L).

What Is the Approximate Molar Concentration of Na+ Ions in a Solution

What Is the Approximate Molar Concentration of Na⁺ Ions in a Solution