Question

Question #9271e

Answer 1

You can't have a 0.250-M calcium hydroxide solution in 100.0 mL of water.

Calcium hydroxide has a solubility of 0.173 g/100mL at `20^@"C"`, which means that you cannot dissolve more than that amount in your volume without creating a saturated solution.

If you calculate the molarity of a 100.0-mL solution prepared by dissolving 0.173 g of calcium hydroxide, you'd get

`0.173cancel("g") * ("1 mole "Ca(OH)_2)/(74.093cancel("g")) = "0.00233 moles "` `Ca(OH)_2`

`C = n/V = "0.00233 moles"/(100 * 10^(-3)"L") = "0.0233 M"`

As you can see, this value is more than 10 times smaller than your target molarity of 0.250 M.