Intermolecular Forces
The forces of attraction between molecules of Cl₂ are?
London forces
What is the name given to the process when solvent molecules surround solute molecules?
Solvation
Which of the following phase changes are endothermic?
1. vaporization
2. sublimation
3. condensation
Which factor(s) increase the solubility of a gas in a solvent?
increasing the partial pressure of the gas and decreasing the temperature
Determine the freezing point of a solution containing 0.31 mol of sucrose in 175 g of water (Kf = 1.86°C/m).
-3.3°C
The forces of attraction between molecules of I₂ are?
London forces
What is the mole fraction of water in a water-ethanol solution that is 54% water by mass?
0.75
The mass of water that must evaporate to dissipate 1.7 × 10⁵ J of heat from the body is?
75.2g
Sparkling wine is bottled under 4.0 atm CO₂, with CO₂ solubility at 0.68 g/100 g H₂O. What is its solubility when opened (4.0 × 10⁻⁴ atm)?
Hint: Use Henry's Law
6.8 × 10⁻⁵ g/100 g H₂O
Calculate the mole fraction of ethanol (C₂H₅OH) in a solution with 46 g ethanol and 64 g methanol (CH₃OH)
0.333
Among N₂, H₂, and CO, which has the highest boiling point?
CO
The number of grams of oxalic acid dihydrate needed to prepare 250.0 mL of 1.25 M solution is?
39.4g
The amount of heat released to convert 20.0 g of mercury vapor at 387°C to liquid at 307°C is?
6.56 kJ
A 500.0 mL sample of water contains 692 μg of lead. What is the concentration in ppm?
1.4 ppm
The vapor pressure of a solution is directly proportional to what property?
Mole fraction of the solvent
Among HF, HBr, HCl, and HI, which has the highest boiling point?
Hint: Which element has the highest electronegativity?
HF
A concentrated H₂SO₄ solution is 65% by mass and has a density of 1.55 g/mL. What is its molality?
18.9m
The triple point of a substance is the temperature and pressure at which the three phases (solid, liquid, and gas) coexist in equilibrium. The triple point of I₂ occurs at 0.12 atm and 115°C. What does this mean?
I₂ is stable at that specific pressure (0.12 atm) and temperature (115°C)
Commercial nitric acid (70% HNO₃, 15.9 M) has what density in g/mL?
1.43 g/mL
The vapor pressure of a solution containing 115 g of urea in 485 g of water at 25°C (P°H₂O = 23.8 mmHg)
Hint: Use formula for Vapor pressure of the solution.
PH₂O= Xwater × P°H₂O
22.2 mmHg
Among covalent solids, molecular solids, metallic solids, and ionic solids, which generally shows electrical conductivity?
Metallic solid
A 1.0 g protein sample (MW = 50,000 g/mol) is dissolved in 50.0 mL of water. What is its osmotic pressure at 25°C?
0.0098 atm
In a certain mountain range, water boils at 95.0C. What is the atmospheric pressure under these conditions, in mm Hg? The heat of vaporization, ∆H vap for H2O is 44.0 kJ/mole, and the normal boiling point of H2O is 100.0C.
HINT: Use the Clausius-Clapeyron equation!
626.8 mmHg
The vapor pressure of diethyl ether is 401 mmHg at 18°C, with ΔHvap = 26 kJ/mol. What is its vapor pressure at 32°C?
654.9 mmHg
What is the mole fraction of water in a water-ethanol solution that is 54% water by mass? (Ethanol MM = 46 g/mol)
0.75