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?
Convert 21.9g KCl to mols. mols = g/molar mass
Then M = mols/L soln.
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 use the formula:
Molarity (M) = moles of solute / volume of solution in liters
First, let's find the moles of KCl. We can do this by dividing the given mass by the molar mass of KCl.
The molar mass of KCl is the sum of the atomic masses of potassium (K) and chlorine (Cl):
M(K) = 39.10 g/mol
M(Cl) = 35.45 g/mol
Molar mass of KCl = M(K) + M(Cl) = 39.10 + 35.45 = 74.55 g/mol
Now, we can find the moles of KCl:
moles of KCl = mass / molar mass = 21.9 g / 74.55 g/mol
Next, we need to convert the volume of the solution from milliliters to liters:
volume of solution = 869 mL = 869/1000 = 0.869 L
Now, we can use the formula to calculate the molarity:
Molarity (M) = moles of solute / volume of solution = (21.9 g / 74.55 g/mol) / 0.869 L
Let's plug in the values and calculate the molarity:
Molarity (M) = (21.9 g / 74.55 g/mol) / 0.869 L ≈ 0.340 M
Therefore, the resulting molarity of the solution would be approximately 0.340 M.