How much calcium hydroxide in grams is needed to produce 1.5 l of a 0.25m solution?

The mass ca (Oh) 2 needed to produce 1.5 l of 0.25 solution is calculated as follows

find moles

=moles = molarity x volume

moles is therefore = 1.5 x 0.25 = 0.375 moles

mass = moles x molar mass

0.375mol x 74.09 g/mol = 27.78 grams