Final answer:
To find the concentration of an electrolyte in a solution, you need to know the molarity and the van't Hoff factor. If the compound is a nonelectrolyte, its concentration is the same as the molarity. If it is a strong electrolyte, determine the number of each ion and find the concentration of each species.
Step-by-step explanation:
To find the concentration of an electrolyte in a solution, you need to know the molarity (moles of solute per liter of solution) and the van't Hoff factor (number of ions produced by each formula unit of the electrolyte when it dissociates). If the compound is a nonelectrolyte, its concentration is the same as the molarity of the solution. If the compound is a strong electrolyte, determine the number of each ion contained in one formula unit. Find the concentration of each species by multiplying the number of each ion by the molarity of the solution.
For example, if you have a solution containing 4.2 g of NaCl dissolved in 125 g of water, you can calculate the molarity by converting the mass of NaCl to moles and dividing by the volume of the solution in liters. Then, you can use the van't Hoff factor for NaCl (2, as it dissociates into Na+ and Cl-) to determine the concentration of each ion by multiplying their respective coefficients (1 for Na+ and 1 for Cl-) by the molarity of the solution.
Example:
- Mass of NaCl = 4.2 g
- Volume of water = 125 g
- Convert mass of NaCl to moles: 4.2 g NaCl * (1 mole NaCl / molar mass of NaCl) = x moles NaCl
- Calculate molarity: x moles NaCl / (volume of water in liters) = y M NaCl
- Calculate concentration of Na+: 1 (coefficient) * y M NaCl = z M Na+
- Calculate concentration of Cl-: 1 (coefficient) * y M NaCl = z M Cl-