how many grams of calcium nitrate are needed to make 100mL of a 0.5M solution
To determine the number of grams of calcium nitrate needed to make a 0.5 M solution in 100 mL, we can use the formula:
Molarity (M) = moles of solute / volume of solution (L)
We know the molarity and volume, so we can rearrange the formula to solve for moles of solute:
moles of solute = Molarity (M) × volume of solution (L)
First, let's convert the volume of the solution from mL to liters:
Volume of solution (L) = 100 mL ÷ 1000 mL/L = 0.1 L
Now, we substitute the values into the formula:
moles of solute = 0.5 M × 0.1 L = 0.05 moles
Finally, to find the mass of calcium nitrate, we need to multiply the moles of solute by its molar mass. The molar mass of calcium nitrate (Ca(NO3)2) can be calculated as follows:
Molar mass of Ca(NO3)2 = (atomic mass of calcium) + (2 × atomic mass of nitrogen) + (6 × atomic mass of oxygen)
= (40.08 g/mol) + (2 × 14.01 g/mol) + (6 × 16.00 g/mol)
= 164.09 g/mol
Now, we can calculate the mass of calcium nitrate:
mass of calcium nitrate = moles of solute × molar mass
= 0.05 moles × 164.09 g/mol
= 8.2045 grams
Therefore, 8.2045 grams of calcium nitrate are needed to make 100 mL of a 0.5 M solution.
moles needed = M x L = ??
moles = g/molar mass.
Solve for grams.