Generally speaking a precipitate is something that will form as a result of the reaction. It generally is a solid material.
Sodium and nitrates are soluble so Calcium Phosphate would precipitate out....
Molality can be expressed by moles of solute over
kilograms of solvent. The question asks the molality of 0.25m NaCl. 0.25m NaCl
is equal to 0.25 moles of NaCl over 1 kg of water.
