UNE - Chem 1011 - Midterm Study Guide
Exam Questions and Answers
The correct expression to calculate the heat required to convert 100 g
of ice starting at -12 °C to liquid water at a final temperature of 85 °C
is:
A. (m x c x ΔT)ice + (n x ΔHfus) + (m x c x ΔT)water
B. (n x ΔHfus) + (m x c x ΔT)water
C. (m x c x ΔT)ice + (m x c x ΔT)water
D. (n x ΔHfus)
A. (m x c x ΔT)ice + (n x ΔHfus) + (m x c x ΔT)water
(Ref: Week 1 Quiz)
the amount of heat absorbed or released by a substance, q, and its
accompanying temperature change, ΔT
q = (m x c x t)
Acetonitrile, CH3CN, is a common solvent used in organic chemistry
labs. Acetonitrile evaporates very quickly at room temperature and
feels noticeably cold when evaporating. If the ΔHvap for acetonitrile is
34.2 kJ/mol, how much heat is removed when 2.3 g of acetonitrile
evaporates?
A. 1.92 kJ
B. 2.76 kJ
C. 3.23 kJ
,D. 0.362 kJ
A. 1.92 kJ
(Ref: Week 1 Quiz) Find the mol of Acetonitrile and multiply it by the
∆Hvap.
An ideal solution
A. is formed with no energy change
B. releases energy when formed
C. absorbs energy when formed
D. has a 1:1 ratio of moles of solute to L of solvent
A. is formed with no energy change
(Ref: Week 2 Quiz)
When a solute is introduced to a solvent
A. energy is required to overcome solute-solute and solvent-solvent
interactions
B. energy is required when solute-solvent interactions are formed
C. a solution will always form
D. a solution will only form if the energy released by solvation is
minimal
A. energy is required to overcome solute-solute and solvent-solvent
interactions
(Ref: Week 2 Quiz)
Non-electrolytes
, A. do not yield ions in solution
B. include all covalent compounds
C. only yield a small fraction of ions in solution
D. dissociate completely in solution
A. do not yield ions in solution
(Ref: Week 2 Quiz)
Which of the following will have the highest conductivity when
dissolved in water?
A. 0.1 M KCl
B. 0.5 M KCl
C. 1.0 M KCl
D. 1.5 M KCl
D. 1.5 M KCL
(Ref: Week 2 Quiz)
The solubility of a gas in a liquid
A. increases as the pressure of the gas increases
B. increases as the temperature of the solution increases
C. decreases as the pressure of the gas increases
D. is the same for all gasses, as long as P, V, n, and T are constant
A. increases as the pressure of the gas increases
Exam Questions and Answers
The correct expression to calculate the heat required to convert 100 g
of ice starting at -12 °C to liquid water at a final temperature of 85 °C
is:
A. (m x c x ΔT)ice + (n x ΔHfus) + (m x c x ΔT)water
B. (n x ΔHfus) + (m x c x ΔT)water
C. (m x c x ΔT)ice + (m x c x ΔT)water
D. (n x ΔHfus)
A. (m x c x ΔT)ice + (n x ΔHfus) + (m x c x ΔT)water
(Ref: Week 1 Quiz)
the amount of heat absorbed or released by a substance, q, and its
accompanying temperature change, ΔT
q = (m x c x t)
Acetonitrile, CH3CN, is a common solvent used in organic chemistry
labs. Acetonitrile evaporates very quickly at room temperature and
feels noticeably cold when evaporating. If the ΔHvap for acetonitrile is
34.2 kJ/mol, how much heat is removed when 2.3 g of acetonitrile
evaporates?
A. 1.92 kJ
B. 2.76 kJ
C. 3.23 kJ
,D. 0.362 kJ
A. 1.92 kJ
(Ref: Week 1 Quiz) Find the mol of Acetonitrile and multiply it by the
∆Hvap.
An ideal solution
A. is formed with no energy change
B. releases energy when formed
C. absorbs energy when formed
D. has a 1:1 ratio of moles of solute to L of solvent
A. is formed with no energy change
(Ref: Week 2 Quiz)
When a solute is introduced to a solvent
A. energy is required to overcome solute-solute and solvent-solvent
interactions
B. energy is required when solute-solvent interactions are formed
C. a solution will always form
D. a solution will only form if the energy released by solvation is
minimal
A. energy is required to overcome solute-solute and solvent-solvent
interactions
(Ref: Week 2 Quiz)
Non-electrolytes
, A. do not yield ions in solution
B. include all covalent compounds
C. only yield a small fraction of ions in solution
D. dissociate completely in solution
A. do not yield ions in solution
(Ref: Week 2 Quiz)
Which of the following will have the highest conductivity when
dissolved in water?
A. 0.1 M KCl
B. 0.5 M KCl
C. 1.0 M KCl
D. 1.5 M KCl
D. 1.5 M KCL
(Ref: Week 2 Quiz)
The solubility of a gas in a liquid
A. increases as the pressure of the gas increases
B. increases as the temperature of the solution increases
C. decreases as the pressure of the gas increases
D. is the same for all gasses, as long as P, V, n, and T are constant
A. increases as the pressure of the gas increases
