Calculate the concentration of all ions present in each of...

Calculate the concentration of all ions present in each of the following solutions of strong electrolytes. a. $0.100$ mole of $\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$ in $100.0 \mathrm{~mL}$ of solution b. $2.5$ moles of $\mathrm{Na}_{2} \mathrm{SO}_{4}$ in $1.25 \mathrm{~L}$ of solution c. $5.00 \mathrm{~g}$ of $\mathrm{NH}_{4} \mathrm{Cl}$ in $500.0 \mathrm{~mL}$ of solution d. $1.00 \mathrm{~g} \mathrm{~K}_{2} \mathrm{PO}_{4}$ in $250.0 \mathrm{~mL}$ of solution

Calculate the concentration of all ions present in each of the following solutions of strong electrolytes.
a. $0.100$ mole of $\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$ in $100.0 \mathrm{~mL}$ of solution
b. $2.5$ moles of $\mathrm{Na}_{2} \mathrm{SO}_{4}$ in $1.25 \mathrm{~L}$ of solution
c. $5.00 \mathrm{~g}$ of $\mathrm{NH}_{4} \mathrm{Cl}$ in $500.0 \mathrm{~mL}$ of solution
d. $1.00 \mathrm{~g} \mathrm{~K}_{2} \mathrm{PO}_{4}$ in $250.0 \mathrm{~mL}$ of solution

Key Concepts

Mass to Moles Conversion

When the amount of an electrolyte is given in grams rather than moles, it is essential to convert the mass to moles using the molar mass of the substance. This conversion is a fundamental step in the process because it allows you to apply the dissociation stoichiometry and molarity concepts to calculate the concentration of ions.

Volume Conversion

Proper volume conversion is necessary when the volume of the solution is provided in units such as milliliters rather than liters. Converting the volume to liters ensures that the concentration calculations (molarity) are accurate because molarity is based on liters of solution.

Dissociation Reaction Stoichiometry

Understanding the stoichiometry of the dissociation reaction is crucial because it tells you exactly how many moles of each ion are produced from each mole of the electrolyte. By using the balanced equation, you can determine the ratio between the initial solute and the resulting ions, ensuring that the computed ion concentrations reflect these ratios.

Strong Electrolyte Behavior

This concept refers to substances that dissociate completely into their ions when dissolved in water. In the context of calculating ion concentrations, it means that every formula unit of the solute will produce a predictable number of ions, which simplifies the computation because there is no need to account for any equilibrium between undissociated and dissociated species.

Molarity Calculation

Molarity is defined as the number of moles of solute per liter of solution. This concept is fundamental for converting the amount of dissolved substance (in moles) into a concentration value expressed in molarity, which is essential for quantifying the concentration of ions in a solution.