Condition I is true. The only place three phases can coexist is at the triple point.

Condition II is false. Water in fact can undergo deposition and move from the solid phase to the gas phase directly. This occurs at pressures below 0.006atm.

Condition III is false. A peculiar fact of the water phase diagram is the slope of the solid/liquid line. For most phase diagrams, the slope is sharply positive, but that of water is negative.

Condition IV is true. No distinct phases exist above the critical point. 

Generally speaking, carbonate salts are insoluble, unless the carbonate is paired with an alkali metal. Magnesium carbonate, as a result, is considered an insoluble salt.

Salts containing alkali metals, ammonium, or nitrate ions are considered soluble. Phosphates, on the other hand, are generally considered insoluble, unless paired with an alkali metal or ammonium ion.

The question states that base A precipitates in a solution of water. We can conclude from this information that base A must be water insoluble. Recall that compounds that are hydrophobic tend to aggregate together when placed water, forming solid precipitates in the solution; therefore, base A must be a hydrophobic base. Base B, on the other hand, is soluble in water and doesn’t precipitate; therefore, base B must be a hydrophilic base.

Solubility rules state that all hydroxide compounds are insoluble in water, except sodium and potassium hydroxide. Calcium hydroxide is water insoluble and could possibly be the identity of base A.

Hydrophilic molecules, by definition, are soluble in water. A compound’s solubility in water can be determined qualitatively using the solubility rules. If we look at the solubility rules, we will notice that there are three main cations that are always soluble in water. This means that a compound containing one of these three cations will always be soluble in water. The three cations are sodium, potassium and ammonium ions. Recall that sodium and potassium are alkali metals (column I of periodic table); therefore, these elements have one electron in its outermost shell (valence electron).

Alkali earth metals are on the second column of periodic table and have two valence electrons. Not all alkali earth metal containing compounds are water soluble (for example, calcium hydroxide).

Recall that interior of a cell membrane is highly nonpolar (due to the nonpolar tails of the cell membrane). Compounds that traverse the interior of a lipophilic membrane must be nonpolar. To solve this question, we need to figure out which compounds are nonpolar. Remember that all nitrates are soluble in water and, therefore, are polar. All alkali metal containing compounds (column I of periodic table) are soluble in water. This means that sodium chloride is water soluble because it contains sodium. Most carbonate salts are insoluble in water, including calcium carbonate; however, note that the calcium carbonate has polar groups with different electronegativities. This means that even though calcium carbonate is insoluble in water it contains polarity and therefore is not lipophilic. None of the compounds listed can traverse through a lipophilic membrane.

The intermolecular forces from strongest to weakest are ionic, hydrogen bonding, dipole-dipole, then London dispersion forces. All compounds experience some form of London dispersion force, but the force only becomes relevant if no other forces are contributing to the attraction of molecules or atoms.

Ethanol will not form ions in solution, so we are left with the other three options as plausible answers. Of the three, the strongest force is hydrogen bonding, which only occurs if a hydrogen is directly attached to a nitrogen, oxygen, or fluorine in the molecule. Ethanol has a hydrogen attached to an oxygen, and is thus capable of hydrogen bonding.

Since we were told that all the liquids have equal volumes, the masses of the liquids for those volumes will determine which liquid is the most dense. The most dense liquid will sink to the bottom, and the least dense liquid will rise to the top. We know that the milk was underneath the water in the beaker, so we can conclude that milk has a greater density than water.

There are three main gas laws. Avogadro’s law states that the moles of a gas is directly proportional to the volume (under constant pressure and temperature). Boyle’s law states that the pressure of the gas is inversely proportional to the volume (under constant moles and temperature). This means that the pressure decreases proportionally when the volume increases. Charles’ law states that the temperature is directly proportional to the volume (under constant moles and pressure). The question states that the piston moves up. This means that the volume of the gas is expanding inside and pushing the piston up to make room for the expanding gas. The gas expansion occurs due to increased temperature (Charles’ law).