CH 222 Oregon State University Week 6 Worksheet Notes

Home , Phase diagram, Supercritical fluid, Triple point

1. Place the following compounds in order of decreasing strength of intermolecular forces.

HF O2 CO2

HF > CO2 > O2

2. In liquid propanol, CH3CH2CH2OH, which intermolecular forces are present?

Dispersion, hydrogen bonding and dipole-dipole forces are present.

3. Assign the appropriate labels to the phase diagram shown below.

A) A = liquid, B = solid, C = gas, D = critical point B) A = gas, B = solid, C = liquid, D = triple point C) A = gas, B = liquid, C = solid, D = critical point D) A = solid, B = gas, C = liquid, D = supercritical fluid E) A = liquid, B = gas, C = solid, D = triple point

4. Consider the phase diagram below. If the dashed line at 1 atm of pressure is followed from 100 to 500°C, what phase changes will occur (in order of increasing temperature)?

A) condensation, followed by vaporization B) sublimation, followed by deposition C) vaporization, followed by deposition D) fusion (melting), followed by vaporization E) No phase change will occur under the conditions specified.

5. Which of the following solutions will have the highest concentration of chloride ions?

A) 0.10 M NaCl B) 0.10 M MgCl2 C) 0.10 M AlCl3 D) 0.05 M CaCl2 E) All of these solutions have the same concentration of chloride ions.

6. Commercial grade HCl solutions are typically 39.0% (by mass) HCl in water. Determine the molarity of the HCl, if the solution has a density of 1.20 g/mL.

A) 7.79 M B) 10.7 M C) 12.8 M D) 9.35 M E) 13.9 M

7. Choose the statement below that is TRUE.

A) A solution will form between two substances if the solute-solvent interactions are of comparable strength to the solute-solute and solvent-solvent interactions. B) A solution will form between two substances if the solute-solvent interactions are small enough to be overcome by the solute-solute and solvent-solvent interactions. C) A solution will form between two substances if the solute-solute interactions are strong enough to overcome the solvent-solvent interactions. D) A solution will form between two substances only if the solvent-solvent interactions are weak enough to overcome the solute-solvent interactions. E) None of the above are true.

8. What mass (in g) of NH3 must be dissolved in 475 g of methanol to make a 0.250 m solution?

2.02 g