Multiple Choice
What is the concentration of carbonate ions (CO3^2−) in a 0.090 M carbonic acid (H2CO3) solution, assuming complete dissociation?
325
views
6. Chemical Quantities & Aqueous Reactions
Solution Stoichiometry
Multiple Choice
What is the mass of chloride ions in 375.0 mL of solution with a magnesium chloride concentration of 0.250 M?
A
26.6 g
B
13.3 g
C
3.33 g
D
6.65 g
Verified step by step guidance1
Determine the number of moles of magnesium chloride (MgCl₂) in the solution using the formula: \( \text{moles} = \text{molarity} \times \text{volume in liters} \). Convert 375.0 mL to liters by dividing by 1000.
Calculate the moles of MgCl₂ using the given molarity (0.250 M) and the volume in liters from the previous step.
Understand that each formula unit of MgCl₂ dissociates into one Mg²⁺ ion and two Cl⁻ ions. Therefore, the moles of Cl⁻ ions will be twice the moles of MgCl₂.
Calculate the moles of Cl⁻ ions by multiplying the moles of MgCl₂ by 2.
Convert the moles of Cl⁻ ions to mass using the molar mass of chloride ions (Cl⁻), which is approximately 35.45 g/mol. Use the formula: \( \text{mass} = \text{moles} \times \text{molar mass} \).
Related Videos
Related Practice
