CHEM 219 LAB EXAMS 1 TO 4 FULL
QUESTIONS AND SOLUTIONS GRADED A+
◉ Which of the following aqueous solutions would have the highest
boiling point?
A) 1.0 m NaNO3
B) 1.0 m HF
C) 1.0 m C₆H₁₂O₆
D) 1.0 m CaCl2
Answer: The dissolved solute will raise the boiling point. The more
"things" that are dissolved (ions or molecules), the higher the boiling
point will be. The CaCl₂ will break up into one Ca²⁺ ion and two Cl⁻
ions and there will be a concentration of 3.0 m of "things" in
solution. The other choices will have fewer "things" in solution and
will raise the boiling point less.
◉ Which one of the following aqueous solutions would have the
highest freezing point?
A) 1.0 m NaNO3
B) 2.0 m CH3OH
C) 1.0 m C₆H₁₂O₆
,D) 1.0 m CaCl2
Answer: The dissolved solute will lower the freezing point. The more
"things" that are dissolved (ions or molecules), the lower the
freezing point will be. Since C₆H₁₂O₆ is a molecule, it will not break
apart and there will only be a concentration of 1.0 m of molecules in
solution. It will lower the freezing point less than all the other
choices. There will be fewer "things" in solution and this will lower
the freezing point less than the other choices.
◉ isoelectronic ions
Answer: ions containing the same number of electrons
◉ Which of the following bonds is the most polar?
Answer: Elements that are located far away from each other on the
periodic table have larger electronegativity differences and
therefore make more polar bonds. Of all the element pairs listed, Rb
and Br are the farthest apart.
◉ Three blocks of the same shape and size are placed in front of you.
Block A has a mass of 3.0 g, block B is 5.0 g, and block C is 10.0 g.
Which has the higher density?
Answer: Density is the ratio of mass to volume. Since the volume is
constant between all the blocks, then the block with the highest
mass will have the highest density.
, ◉ Density equation
Answer: mass/volume
dRT = PM
◉ The solubility of a gas in a liquid generally
A) increases with increasing temperature.
B) increases with decreasing temperature.
C) increases with increasing pressure.
D) both (a) and (c).
E) both (b) and (c).
Answer: E) both (b) and (c)
◉ Which of the following properties, in general, increase as we move
left to right across a period in the periodic table?
1. atomic radius
2. ionization energy
3. metallic character
A) 1 only
B) 2 only
QUESTIONS AND SOLUTIONS GRADED A+
◉ Which of the following aqueous solutions would have the highest
boiling point?
A) 1.0 m NaNO3
B) 1.0 m HF
C) 1.0 m C₆H₁₂O₆
D) 1.0 m CaCl2
Answer: The dissolved solute will raise the boiling point. The more
"things" that are dissolved (ions or molecules), the higher the boiling
point will be. The CaCl₂ will break up into one Ca²⁺ ion and two Cl⁻
ions and there will be a concentration of 3.0 m of "things" in
solution. The other choices will have fewer "things" in solution and
will raise the boiling point less.
◉ Which one of the following aqueous solutions would have the
highest freezing point?
A) 1.0 m NaNO3
B) 2.0 m CH3OH
C) 1.0 m C₆H₁₂O₆
,D) 1.0 m CaCl2
Answer: The dissolved solute will lower the freezing point. The more
"things" that are dissolved (ions or molecules), the lower the
freezing point will be. Since C₆H₁₂O₆ is a molecule, it will not break
apart and there will only be a concentration of 1.0 m of molecules in
solution. It will lower the freezing point less than all the other
choices. There will be fewer "things" in solution and this will lower
the freezing point less than the other choices.
◉ isoelectronic ions
Answer: ions containing the same number of electrons
◉ Which of the following bonds is the most polar?
Answer: Elements that are located far away from each other on the
periodic table have larger electronegativity differences and
therefore make more polar bonds. Of all the element pairs listed, Rb
and Br are the farthest apart.
◉ Three blocks of the same shape and size are placed in front of you.
Block A has a mass of 3.0 g, block B is 5.0 g, and block C is 10.0 g.
Which has the higher density?
Answer: Density is the ratio of mass to volume. Since the volume is
constant between all the blocks, then the block with the highest
mass will have the highest density.
, ◉ Density equation
Answer: mass/volume
dRT = PM
◉ The solubility of a gas in a liquid generally
A) increases with increasing temperature.
B) increases with decreasing temperature.
C) increases with increasing pressure.
D) both (a) and (c).
E) both (b) and (c).
Answer: E) both (b) and (c)
◉ Which of the following properties, in general, increase as we move
left to right across a period in the periodic table?
1. atomic radius
2. ionization energy
3. metallic character
A) 1 only
B) 2 only
