Please help ASAP. If you know the answer to few of the parts then tell me the answer to the part you know with explanation and also type the letter of which part you solved

How to convert a density of 0.791g/cm3 to lb/ft3

Assuming complete dissociation of the solute, how many grams of kno3 must be added to 275 ml of water to produce a solution that freezes at -14.5 c? the freezing point for pure water is 0.0 c and k_f is equal to 1.86 c/m

Asample of tin (ii) chloride has a mass of 0.49 g. after heating, it has a mass of 0.41 g.  what is the percent by mass of water in the hydrate?   %