portuhitles for hydrogen bonding to (D) Heptane has a carbon chain that is further apart making it less stable. 16. Which of the following would be expected to have the lowest vapor pressure at 25°C? (A) N2 (B) Cl, (С) Brz (D) L2 sllame botudicte 19. In which of the following pairs of substances is the substance with the higher expected melting point listed first? (A) KCl or NaCl (B) Mg or Al (C) Ba or Cs (D) Ar or Kr al ad MOo ise boyoe mos H ba 1o sianoo lelaygo ed qu alam olog 20. Which of the substances below would be expected to have the lowest boiling point at 1 atm pressur (A) (bent) F-O-F ) KOH wapichare clotive number of dissolved particles remaining O=0 ( (D) [Li*][CH] Combonuq VNC loh 21. Which factor(s) account for the observed difference in boiling points for the compounds below? ai esononib Ethane CH,CH3 Propane CH,CH,CH, Compound -42°C Boiling point (A) stronger dipole-dipole attractions between propane molecules (B) a larger number of covalent bonds within the propane molecule a larger molar mass and more internal bonding in propane molecules (D) a larger surface area and larger electron cloud in propane molecules

At three different temperatures, T1, T2, and T3, the moleculesin a liquid crystal align in these ways:T1(a) At which temperature or temperatures is the substancein a liquid crystalline state? At those temperatures, whichtype of liquid crystalline phase is depicted? (b) Which is thehighest of these three temperatures? [Section 11.7]

The vapor pressure of liquid SO, is 281.1 mmHg at a temperature of 242.0 K. The enthalpy of vaporization, AH, What is the vapor pressure of SO2 at a temperature of 250.0 K, in mmHg? for this liquid is 24.9 kJ/mol. чар"

Prior to the discovery that freon-12 (CF2Cl2) was harmful to the Earth's ozone layer, it was frequently used as the dispersing agent in spray cans for hair spray, etc. Its enthalpy of vaporization at its normal boiling point of -29.2 degree C is 20.25 kJ/mol. Estimate the pressure that a can of hair spray using freon-12 had to withstand at 40 degree C, the temperature of a can that has standing in sunlight.

How much heat must be added to 100 g of ice at -5°C to turn it into 60 grams of water and 40 grams of steam, both at 100°C? Cp H2O = 75.7 J/mol-K, Cp Ice = 37.7 J/mol-K, Cp Steam = 35.1 J/mol-K, ΔHfus = 6.01 kJ/mol, ΔHvap = 40.7 kJ/mol

Study the following phase diagram of Substance X. A B C E- F temperature (K) A C If a sample of pure X is solid, in which region must the temperature and pressure be? G H A Which line must the temperature and pressure have crossed if a gaseous sample of X is observed to condense? H А В Which is the critical point of X? E O F G он O O OO O C ш о O O O OlO O O OO O O O pressure (atm)

The compounds Br2 and ICI have the same number of electrons, yet Br2 melts at -7.2C, whereas ICI melts ar 27.3C. Explain.I am very confused on how to even begin a question like this-if you could fully explain how to do it etc.