An aqueous solution is 28.0% by mass potassium bromide, , and has a density of 1.24 g/mL. what is the molarity of potassium bromide

To calculate the molarity (M) of potassium bromide (KBr) in the aqueous solution, we'll need to follow these steps:

### Given dataTo calculate the molarity (M) of potassium bromide (KBr) in the aqueous solution, we'll need to follow these steps:

### Given 
1. The mass percentage of potassium bromide is 28.0%.
2. The density of the solution is 1.24 g/mL.
3. The molar mass of potassium bromide (KBr) is approximately 119.0 g/mol.

### Step 1: Assume 100 g of solution.
In this case, 28.0 g of potassium bromide (KBr) is present in the solution (because it's 28.0% by mass).

### Step 2: Calculate the mass of the solvent.
The remaining 72.0 g of the solution is water (the solvent).

### Step 3: Calculate the volume of the solution.
Since the density is given as 1.24 g/mL, we can calculate the volume using the formula:

\[
\text{Volume} = \frac{\text{Mass}}{\text{Density}} = \frac{100 \, \text{g}}{1.24 \, \text{g/mL}} = 80.65 \, \text{mL} = 0.08065 \, \text{L}
\]

### Step 4: Calculate moles of KBr.
The number of moles of potassium bromide (KBr) is calculated using its mass and molar mass:

\[
\text{Moles of KBr} = \frac{28.0 \, \text{g}}{119.0 \, \text{g/mol}} = 0.2353 \, \text{mol}
\]

### Step 5: Calculate the molarity.
Molarity (M) is defined as moles of solute per liter of solution:

\[
\text{Molarity} = \frac{\text{Moles of KBr}}{\text{Volume of Solution in Liters}} = \frac{0.2353 \, \text{mol}}{0.08065 \, \text{L}} = 2.92 \, \text{M}
\]

### Final Answer:
The molarity of the potassium bromide (KBr) in the solution is approximately **2.92 M**.

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Would you like more details on this solution? Here are some related questions:

1. How do molality and molarity differ, and how do you convert between them?
2. How would the molarity change if the solution was diluted?
3. What is the significance of solution density in concentration calculations?
4. How can we calculate molarity for a solute in a non-aqueous solvent?
5. How does temperature affect the density and concentration of solutions?

**Tip:** Always check if the solution is ideal (meaning the solute doesn't significantly change the solvent's volume), as this can slightly affect molarity in precise applications.

An aqueous solution is 28.0% by mass potassium bromide, and has a density of 1.24 g/mL. What is the molarity of potassium bromide?

Learn how to calculate the molarity of potassium bromide in an aqueous solution that is 28.0% by mass and has a density of 1.24 g/mL. This problem covers concepts such as molarity, mass percentage, and solution volume calculation, ideal for students in Grades 10-12.

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