Final answer:
To find the molarity of a calcium hydroxide solution, convert the given mass to moles using the molar mass of Ca(OH)2, then divide by the volume in liters. Resulting in a molarity of 0.070 M for the solution.
Step-by-step explanation:
To calculate the molarity of a solution containing calcium hydroxide, Ca(OH)₂, we first need to determine the moles of solute.
Given that the mass of Ca(OH)₂ is 0.2074 g and knowing its molar mass is approximately 74.09 g/mol, we can calculate the number of moles using the formula:
- moles = mass (g) / molar mass (g/mol)
The moles of Ca(OH)₂ are calculated as follows:
- moles = 0.2074 g / 74.09 g/mol = 0.0028 mol (rounded to three significant figures)
To find the molarity, we divide the moles of solute by the volume of the solution in liters:
- molarity (M) = moles of solute / volume of solution (L)
With a solution volume of 40.00 ml or 0.04000 L, we determine the molarity:
- molarity = 0.0028 mol / 0.04000 L = 0.070 M (rounded to two significant figures)
Therefore, the molarity of the calcium hydroxide solution is 0.070 M.