The addition of 6 g of salt to a sample of pure water causes its freezing point to be reduced from 0°C to -1.5°C. After an additional amount of salt is dissolved in the solution, its freezing point is -4.5°C. What is the total amount of salt dissolved in the sample of water?

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample? a. naphthalene, a molecular solid with the formula c10h8 b. silica, a network solid held together by covalent bonds with the formula sio2 c. calcium chloride, an ionic compound with the formula cacl2 d. water, an molecular compound with the formula h2o