Calculate the molarity of Na2C204 solution prepared by dissolving 1.2222 grams of pure Na2C204 in enough water to make 500.00 mL of solution.
To calculate the molarity (M) of a solution, you need to know the moles of solute and the volume of the solution in liters.
Step 1: Calculate the moles of Na2C204:
First, find the molar mass of Na2C204.
The molar mass of Na is 22.99 g/mol (sodium)
The molar mass of C2O4 is 60.01 g/mol (oxalate)
Na2C204 has two sodium atoms, one carbon atom, and four oxygen atoms:
(2 * 22.99 g/mol) + (1 * 12.01 g/mol) + (4 * 16.00 g/mol) = 134.05 g/mol
Now, use the given mass of Na2C204 to calculate the moles:
moles of Na2C204 = mass / molar mass
moles of Na2C204 = 1.2222 g / 134.05 g/mol
Step 2: Calculate the volume of the solution in liters:
The given volume is 500.00 mL. To convert this to liters, divide by 1000:
volume of solution = 500.00 mL / 1000 = 0.500 L
Step 3: Calculate the molarity (M):
Molarity (M) = moles / volume of solution in liters
Molarity (M) = moles of Na2C204 / volume of solution
Substituting the values:
Molarity (M) = (1.2222 g / 134.05 g/mol) / 0.500 L
Simplify the expression:
Molarity (M) = 0.00912 mol / 0.500 L
Molarity (M) ≈ 0.018 M
Therefore, the molarity of the Na2C204 solution is approximately 0.018 M.