CHEM 219 MODULES 1–8 EXAMS
& FINAL EXAM – PRINCIPLES OF
ORGANIC CHEMISTRY (2026/2027)
| PORTAGE LEARNING –
VERIFIED Q&A
_________ is a measure of the tendency of a material to change into the gaseous
state - ANSWER - Vapor pressure is a measure of the tendency of a material to
change into the gaseous state. The molecules are moving rapidly and if they have
enough energy they will escape from the liquid.
(NH₄)₂SO₄ has a van't Hoff factor of i = 2.3. What is the concentration of particles
in a 0.7801 M solution of (NH₄)₂SO₄? - ANSWER - 1.8 M
2.3 x 0.7801 = 1.8
M=(i)x(M)
A solution is an example of - ANSWER - A solution is defined as a homogeneous
mixture.
A solution is made by dissolving 2.5 mg sodium fluoride (NaF) in 1.5 L of water at
20.0°C. What is the fluoride ion concentration in ppm of the resulting solution,
given that NaF is 45.0% fluoride ion by mass, and the density of water of 1.00
kg/L? - ANSWER - 2.5 x 45/100 = 1.125mg
weight of ion / weight of water = ppm
so, 1.5L = 1.5 Kg
, 1.125mg / 1.5 kg = 0.75
A solution is made using 163.7 g of dimethyl ether (MM = 46.07 g/mol) and 90.0 g
of methanol (MM = 32.04 g/mol). What is the mole fraction of the dimethyl ether
in the solution? - ANSWER - find mol of dim & methanol
dim mol / dim mol + methanol = mol fraction
A solution is made using 175.7 g of hexane (MM = 86.18 g/mol) and 200.0 g of
octane (MM = 114.2 g/mol). What is the molality of the hexane in the solution? -
ANSWER - m = (W g of solute / Molar mass of solute) (1000 / W g of solvent)
(175.7g / 86.18g/mol) ( g) = 10.19m
All will contribute equally. Because boiling point elevation is a colligative property,
it depends only on the concentration of solute, not the type of solute. - ANSWER -
Vapor pressure describes the tendency of a substance to change from the liquid
to the gas phase, so substances with weaker intermolecular forces will have
higher vapor pressures. A substance's boiling point is also indicative of the
strength of the intermolecular forces, with weaker intermolecular forces resulting
in lower boiling points. Because acetone has the lowest boiling point of the
options given, it has the weakest intermolecular forces, and will therefore have
the highest vapor pressure.
Amonton's Law - ANSWER - if the volume of a gas is held constant, increasing the
temperature of the gas increases its pressure.
At a particular temperature, the solubility of H₂ in water is 0.140 M when the
partial pressure is 1.20 atm. What partial pressure (in atm) of H₂ would give a
solubility of 4.95 M? - ANSWER - 42.4 atm
& FINAL EXAM – PRINCIPLES OF
ORGANIC CHEMISTRY (2026/2027)
| PORTAGE LEARNING –
VERIFIED Q&A
_________ is a measure of the tendency of a material to change into the gaseous
state - ANSWER - Vapor pressure is a measure of the tendency of a material to
change into the gaseous state. The molecules are moving rapidly and if they have
enough energy they will escape from the liquid.
(NH₄)₂SO₄ has a van't Hoff factor of i = 2.3. What is the concentration of particles
in a 0.7801 M solution of (NH₄)₂SO₄? - ANSWER - 1.8 M
2.3 x 0.7801 = 1.8
M=(i)x(M)
A solution is an example of - ANSWER - A solution is defined as a homogeneous
mixture.
A solution is made by dissolving 2.5 mg sodium fluoride (NaF) in 1.5 L of water at
20.0°C. What is the fluoride ion concentration in ppm of the resulting solution,
given that NaF is 45.0% fluoride ion by mass, and the density of water of 1.00
kg/L? - ANSWER - 2.5 x 45/100 = 1.125mg
weight of ion / weight of water = ppm
so, 1.5L = 1.5 Kg
, 1.125mg / 1.5 kg = 0.75
A solution is made using 163.7 g of dimethyl ether (MM = 46.07 g/mol) and 90.0 g
of methanol (MM = 32.04 g/mol). What is the mole fraction of the dimethyl ether
in the solution? - ANSWER - find mol of dim & methanol
dim mol / dim mol + methanol = mol fraction
A solution is made using 175.7 g of hexane (MM = 86.18 g/mol) and 200.0 g of
octane (MM = 114.2 g/mol). What is the molality of the hexane in the solution? -
ANSWER - m = (W g of solute / Molar mass of solute) (1000 / W g of solvent)
(175.7g / 86.18g/mol) ( g) = 10.19m
All will contribute equally. Because boiling point elevation is a colligative property,
it depends only on the concentration of solute, not the type of solute. - ANSWER -
Vapor pressure describes the tendency of a substance to change from the liquid
to the gas phase, so substances with weaker intermolecular forces will have
higher vapor pressures. A substance's boiling point is also indicative of the
strength of the intermolecular forces, with weaker intermolecular forces resulting
in lower boiling points. Because acetone has the lowest boiling point of the
options given, it has the weakest intermolecular forces, and will therefore have
the highest vapor pressure.
Amonton's Law - ANSWER - if the volume of a gas is held constant, increasing the
temperature of the gas increases its pressure.
At a particular temperature, the solubility of H₂ in water is 0.140 M when the
partial pressure is 1.20 atm. What partial pressure (in atm) of H₂ would give a
solubility of 4.95 M? - ANSWER - 42.4 atm
