An aqueous solution is 15.0 % by mass of copper(II) sulfate...

An aqueous solution is $15.0 \%$ by mass of copper(II) sulfate pentahydrate, $\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O} .$ What is the molarity of $\mathrm{CuSO}_{4}$ in this solution at $20^{\circ} \mathrm{C}$ ? The density of this solution at $20^{\circ} \mathrm{C}$ is $1.167 \mathrm{~g} / \mathrm{mL}$

Key Concepts

Hydrated Salts and Stoichiometry

Hydrated salts contain a specified number of water molecules bound to each formula unit of the salt. In calculations, it is important to correctly account for the water of hydration when determining the molar mass of the compound, and then use the mole ratio to relate the hydrated compound to the anhydrous part if necessary.

Molarity

Molarity is a measure of the concentration of a solute in a solution, defined as the number of moles of solute per liter of solution. It is widely used in chemistry to relate quantities in reactions and to perform stoichiometric calculations.

Molar Mass Calculation

Calculating the molar mass involves summing the atomic masses of the elements in the compound. This step is crucial when converting mass of a substance to moles, particularly in converting a percentage concentration by mass into moles for molarity computations.

Density of a Solution

Density is defined as the mass per unit volume of a substance. In solution calculations, density is used to convert the mass of the solution to its volume (or vice versa), which is essential when the concentration is to be expressed in molarity, i.e., moles per liter.

Percent Composition by Mass

This concept refers to the ratio of the mass of the solute to the total mass of the solution, expressed as a percentage. It is important for determining the amount of solute present in a given mass of solution and is a common method for expressing concentration in laboratories.

Transcript

Please give Ace some feedback