1) The bonds in the polyatomic ion (CO3)^2- are classified as
A) ionic
B) metallic
C) nonpolar covalent
D) polar covalent
2) Which of the following phase changes has a positive value for its entropy change?
A) boiling water
B) formation of raindrops from a cloud
C) making dry ice from gaseous CO2
D) making ice cubes from liquid water
3) Molecules of a liquid can pass into the vapor phase only if the
A) liquid has little surface tension.
B) molecules have sufficient kinetic energy to overcome the intermolecular forces in the liquid.
C) temperature of the liquid is near its boiling point.
D) vapor pressure of the liquid is high.
4) Which drawing best shows the direction of the dipole moment in H2C=CCl2?
A) drawing (1)
B) drawing (2)
C) drawing (3)
D) drawing (4)
5) Which drawing below best represents hydrogen bonding methanol, CH3OH?
A) drawing (1)
B) drawing (2)
C) drawing (3)
D) drawing (4)
6) If figure (1) represents the vapor pressure of water at 25 °C, which figure represents the vapor pressure of ethanol, CH3CH2OH at 25 °C?
A) figure (2)
B) figure (3)
C) figure (4)
The plots below represent vapor pressure vs. temperature curves for diethyl ether, ethanol, mercury, and water, not necessarily in that order.
7) Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for ethanol?
A) curve (a)
B) curve (b)
C) curve (c)
D) curve (d)
8) Identify the solid packing in the figure shown below.
A) body-centered cubic
B) cubic closest packed (face-centered cubic)
C) hexagonal closest packed
D) simple cubic
9) What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 144 pm?
A) 481 pm
B) 362 pm
C) 407 pm
D) 302 pm
Use the diagram below to answer the following questions.
10) According to the diagram, the solid and liquid phases can exist in equilibrium along line
A) AC.
B) CB.
C) CD.
D) BD.
11) What phase changes occur when the pressure is held constant at 0.25 atm and the temperature increases from 100 °C to 300 °C?
A) liquid â†' gas
B) solid â†' gas
C) solid â†' liquid
D) solid â†' liquid â†' gas