What would be the resulting molarity of a solution made by dissolving 21.9 grams of KCl in enough water to make an 869-milliliter solution? Show all of the work needed to solve this problem.
To find the resulting molarity of the solution, we need to follow a few steps:
Step 1: Convert grams of KCl to moles.
The molar mass of KCl is 74.55 g/mol (potassium: 39.1 g/mol, chlorine: 35.45 g/mol).
Using the formula: moles = mass (in grams) / molar mass
moles KCl = 21.9 g / 74.55 g/mol
moles KCl ≈ 0.294 moles
Step 2: Convert milliliters of the solution to liters.
1 liter is equal to 1000 milliliters.
Liters = milliliters ÷ 1000
Liters = 869 ml / 1000
Liters = 0.869 L
Step 3: Calculate molarity using the formula:
Molarity = moles of solute / liters of solution
Molarity = 0.294 moles / 0.869 L
Molarity ≈ 0.338 M
Therefore, the resulting molarity of the solution made by dissolving 21.9 grams of KCl in enough water to make an 869-milliliter solution is approximately 0.338 M.