Passage
Water is unique in that all three of its phases exist over a small range of pressures and temperatures, as shown in Figure 1.
Figure 1 Phase diagram for waterIn the liquid phase, water dissolves and transports molecules, and aids in the biochemical reactions necessary to support life. For this reason, scientists believe liquid-phase water is essential to the existence of extraterrestrial life. Although it has been known for some time that water is present in both the gas and ice phases on Mars, the question remains as to whether there are regions where liquid-phase water can stably exist. Estimates of Mars' surface temperature and pressure generated from satellite readings and global climate models, as well as observations made by Mars rovers, reveal that surface conditions on the planet can vary greatly.Table 1 Temperature and Pressure of Various Locations on Mars
Despite the extremely low pressures and temperatures on Mars, satellite images have repeatedly found evidence of flowing liquid water in several regions during the late Martian summer season. These regions, called recurring slope lineae (RSL) , are hypothesized to be thermodynamically stable under certain Martian conditions due to the presence of dissolved salts. A simple understanding of this hypothesis is afforded by Raoult law, which states that the vapor pressure and freezing point of an ideal solution are lowered as the number of moles of dissolved solute increases. Moreover, this effect also impacts the solution boiling point (the point at which the vapor pressure of the solution becomes equal to the ambient pressure) .The briny-water hypothesis was confirmed in 2015 when spectral data from the Compact Reconnaissance Imaging Spectrometer onboard the Mars Reconnaissance Orbiter revealed the presence of hydrated perchlorates in the same regions and times that RSL were observed. Studies are already underway to determine how common such briny water flows are and whether the conditions within them are suitable for microbial life.
-Which of the following molecules is unable to form hydrogen bonds with water?

Question

Passage
Water is unique in that all three of its phases exist over a small range of pressures and temperatures, as shown in Figure 1.

Figure 1 Phase diagram for waterIn the liquid phase, water dissolves and transports molecules, and aids in the biochemical reactions necessary to support life. For this reason, scientists believe liquid-phase water is essential to the existence of extraterrestrial life. Although it has been known for some time that water is present in both the gas and ice phases on Mars, the question remains as to whether there are regions where liquid-phase water can stably exist. Estimates of Mars' surface temperature and pressure generated from satellite readings and global climate models, as well as observations made by Mars rovers, reveal that surface conditions on the planet can vary greatly.Table 1 Temperature and Pressure of Various Locations on Mars

Despite the extremely low pressures and temperatures on Mars, satellite images have repeatedly found evidence of flowing liquid water in several regions during the late Martian summer season. These regions, called recurring slope lineae (RSL) , are hypothesized to be thermodynamically stable under certain Martian conditions due to the presence of dissolved salts. A simple understanding of this hypothesis is afforded by Raoult law, which states that the vapor pressure and freezing point of an ideal solution are lowered as the number of moles of dissolved solute increases. Moreover, this effect also impacts the solution boiling point (the point at which the vapor pressure of the solution becomes equal to the ambient pressure) .The briny-water hypothesis was confirmed in 2015 when spectral data from the Compact Reconnaissance Imaging Spectrometer onboard the Mars Reconnaissance Orbiter revealed the presence of hydrated perchlorates in the same regions and times that RSL were observed. Studies are already underway to determine how common such briny water flows are and whether the conditions within them are suitable for microbial life.
-Which of the following molecules is unable to form hydrogen bonds with water?

Quizplus · Accepted Answer

11ecba2d_11a6_7918_a3bf_ef7abba3640f_MD0008_00 Hydrogen bonding is a strong intermolecular force that occurs between a hydrogen atom on one molecule and an electronegative atom with a lone electron pair on another molecule. The hydrogen atom is the bond donor and must be covalently attached to a small electronegative atom that withdraws electrons from hydrogen, giving it a partial positive charge. The partial positive charge is then attracted to the partial negative charge of the lone pair of electrons in the bond acceptor. These interactions can only occur over short distances, so they require sufficiently small electronegative atoms in both the donor and acceptor molecules, and are essentially limited to fluorine, nitrogen, and oxygen. Carbon is a small atom but not sufficiently electronegative to participate in hydrogen bonding. On the other hand, bromine is electronegative but too large to participate in hydrogen bonding. Therefore, C₂H₄Br₂ is unable to form hydrogen bonds with water. (Choices B, C, and D) The partial positive charge on the hydrogen atom in water can form hydrogen bonds with the electronegative nitrogen, oxygen, and fluorine atoms in C₃H₉N, C₉H₁₈O₂, and C₂F₄, respectively. Educational objective: Hydrogen bonding occurs when a partially positive hydrogen atom in one molecule is attracted to the partial negative charge on an electronegative atom in another molecule. Atoms involved in hydrogen bonding must have small atomic radii, and are essentially limited to fluorine, oxygen, and nitrogen.

Passage Water Is Unique in That All Three of Its Phases