A sample of calcium nitrate with a mass of 1.00 g was dissolved in water and diluted to 100.00 mL in a volumetric flask. What is the concentration of the calcium nitrate ?
To determine the concentration of calcium nitrate, we need to calculate the molarity (M) of the solution. Molarity is defined as the number of moles of solute per liter of solution.
First, we need to convert the mass of calcium nitrate (1.00 g) to moles. To do this, we divide the mass by the molar mass of calcium nitrate.
The molar mass of calcium nitrate (Ca(NO3)2) is:
Ca: 1 atom x 40.08 g/mol = 40.08 g/mol
N: 2 atoms x 14.01 g/mol = 28.02 g/mol
O: 6 atoms x 16.00 g/mol = 96.00 g/mol
Adding these values together, we get:
40.08 g/mol + 28.02 g/mol + 96.00 g/mol = 164.10 g/mol
Now, we can calculate the number of moles of calcium nitrate:
moles = mass / molar mass
moles = 1.00 g / 164.10 g/mol = 0.00609 mol
Next, we need to divide the number of moles by the volume of the solution in liters. The volume of the solution is given as 100.00 mL, which is equivalent to 0.100 L (since 1 L = 1000 mL).
Finally, we calculate the concentration (molarity) using the formula:
Molarity (M) = moles / volume (in liters)
Molarity (M) = 0.00609 mol / 0.100 L = 0.061 M
Therefore, the concentration of the calcium nitrate solution is 0.061 M.