Question

At a certain temperature, an aqueous solution is 33.0% koh by mass and has a density of 1.297 g/cm3. what is the molarity of the solution?

Answer 1

The molarity of the solution can be calculated using the formula molarity (M) = moles of solute / volume of solution (in liters). To find the moles of KOH, we first need to calculate the mass of KOH in the solution using the mass percentage. Then, we convert the mass of KOH to moles using the molar mass. Finally, we calculate the volume of the solution using the given density and use it in the molarity formula to get the final molarity result.

Step-by-step explanation:

The molarity of a solution can be calculated by using the formula:

molarity (M) = moles of solute / volume of solution (in liters)

In this case, we are given that the solution is 33.0% KOH by mass and has a density of 1.297 g/cm³. To find the molarity, we need to convert the mass percentage to moles and the density to volume.

Step 1: Calculate the mass of KOH in the solution

Mass of KOH = mass percentage x mass of solution = 33.0% x mass of solution

Step 2: Convert the mass of KOH to moles using the molar mass

Moles of KOH = mass of KOH / molar mass of KOH

Step 3: Convert the density to volume

Volume of solution = mass of solution / density

Step 4: Calculate the molarity

Molarity (M) = Moles of KOH / Volume of solution


Plug in the values and calculate the molarity.