We have an aqueous solution that contains 22% (by mass) of a hypothetical solute Z. The formula weight of the solute Z is 215 g/mol. The density of the solution is observed to be 1.1 g/mL. What is the molarity of Z in this solution?
El,
I will get you started here. You have 22% by mass of solute Z(by mass also means w/w), which means 22 g Z/100 g soln.
22 g Z/100 g soln(1 mol Z/215 g Z)x(1.1g/ml)x(1,000ml/L)=?
1.12558
To find the molarity of solute Z in the solution, we need to first determine the concentration of solute Z in terms of moles per liter.
Step 1: Calculate the mass of solute Z in the solution.
Given that the solution contains 22% of solute Z by mass and the density of the solution is 1.1 g/mL, we can calculate the mass of solute Z in the solution.
Mass of solution = Volume of solution × Density
Since we don't know the volume of the solution, let's assume we have 100 grams of the solution. Therefore,
Mass of solution = 100 g × 1.1 g/mL = 110 g
Mass of solute Z = 22% of mass of solution = 0.22 × 110 g = 24.2 g
Step 2: Calculate the number of moles of solute Z.
To convert grams to moles, we'll use the formula weight of solute Z.
Number of moles = Mass of solute Z / Formula weight of solute Z
Number of moles = 24.2 g / 215 g/mol = 0.1127 mol
Step 3: Calculate the volume of the solution in liters.
To convert the density of the solution from grams per milliliter (g/mL) to grams per liter (g/L) for molarity calculations, we divide by 1000.
Volume of solution = Mass of solution / Density
Volume of solution = 100 g / (1.1 g/mL × 1000 mL/L) = 0.0909 L
Step 4: Calculate the molarity of solute Z.
Molarity (M) is defined as moles of solute per liter of solution.
Molarity of Z = Number of moles / Volume of solution
Molarity of Z = 0.1127 mol / 0.0909 L ≈ 1.237 M
Therefore, the molarity of solute Z in the solution is approximately 1.237 M.