Answer:
To calculate the molarity (M) of a solution, you need to know the amount of solute (in moles) and the volume of the solution (in liters).
Given:
Mass of Mg(NO3)2 = 0.530 g
Volume of solution = 250.0 mL = 0.250 L
To calculate the number of moles of Mg(NO3)2, you need to convert the mass to moles using the molar mass of Mg(NO3)2.
Molar mass of Mg(NO3)2:
Mg: 24.31 g/mol
N: 14.01 g/mol
O: 16.00 g/mol (x3 for three oxygen atoms)
2 nitrogen atoms + 6 oxygen atoms = (14.01 g/mol x 2) + (16.00 g/mol x 6) = 46.02 g/mol
Now, calculate the moles of Mg(NO3)2:
Moles = Mass / Molar mass
Moles = 0.530 g / 46.02 g/mol
Now we have the moles of Mg(NO3)2, and we can calculate the molarity (M) using the formula:
Molarity (M) = Moles / Volume
Molarity = (0.530 g / 46.02 g/mol) / 0.250 L
Calculate the value:
Molarity = 0.0115 mol / 0.250 L
Molarity = 0.046 M (rounded to three decimal places)
Therefore, the molarity of the solution containing 0.530 g of Mg(NO3)2 in 250.0 mL of solution is approximately 0.046 M.