Final answer:
To make a 0.250 M solution of Ca(OH)₂ with a volume of 100 mL, you would need 1.85 grams of Ca(OH)₂.
Step-by-step explanation:
To calculate the grams of Ca(OH)₂ needed to make a 0.250 M solution with a volume of 100 mL, we can use the formula:
moles = concentration (M) x volume (L)
First, we need to convert the volume from mL to L, so 100 mL becomes 0.100 L.
Next, we substitute the given values into the formula:
moles = 0.250 M x 0.100 L = 0.025 moles
Finally, we need to convert moles to grams using the molar mass of Ca(OH)₂. The molar mass of Ca is 40.08 g/mol, the molar mass of O is 16.00 g/mol, and the molar mass of H is 1.01 g/mol.
The molar mass of Ca(OH)₂ is:
(40.08 g/mol) + (2 x 16.00 g/mol) + (2 x 1.01 g/mol) = 74.16 g/mol
Therefore, the number of grams of Ca(OH)₂ needed is:
grams = 0.025 moles x 74.16 g/mol = 1.85 grams