Molarity Calculation: Potassium Iodide Solution

What is the molarity of a solution composed of 5.06 g of potassium iodide (KI) dissolved in enough water to make 0.167 L of solution?

Given:

Mass of potassium iodide = 5.06 g

Volume of solution = 0.167 L

Answer:

The molarity of the solution composed of 5.06 g of potassium iodide (KI) dissolved in enough water to make 0.167 L of solution is 0.182 M.

When calculating the molarity of a solution, we need to consider the mass of the solute and the volume of the solution. In this case, we are dealing with potassium iodide (KI) as the solute.

The first step is to determine the number of moles of KI in the solution. This can be done by using the molar mass of KI, which is calculated by adding the atomic masses of potassium (39.098 g/mol) and iodine (126.904 g/mol), resulting in 166.002 g/mol.

Next, we calculate the number of moles of KI by dividing the given mass of KI (5.06 g) by the molar mass (166.002 g/mol), which gives us 0.0304 mol of KI.

Finally, we can calculate the molarity by dividing the number of moles of KI by the volume of the solution (0.167 L) using the formula: Molarity = (moles of solute) / (volume of solution). Substituting the values, we get a molarity of 0.182 M for the solution.

Therefore, the molarity of the potassium iodide solution is 0.182 M, indicating the concentration of KI in the solution.